/*
** 2001-09-15
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the SQLite library
** presents to client programs.  If a C-function, structure, datatype,
** or constant definition does not appear in this file, then it is
** not a published API of SQLite, is subject to change without
** notice, and should not be referenced by programs that use SQLite.
**
** Some of the definitions that are in this file are marked as
** "experimental".  Experimental interfaces are normally new
** features recently added to SQLite.  We do not anticipate changes
** to experimental interfaces but reserve the right to make minor changes
** if experience from use "in the wild" suggest such changes are prudent.
**
** The official C-language API documentation for SQLite is derived
** from comments in this file.  This file is the authoritative source
** on how SQLite interfaces are supposed to operate.
**
** The name of this file under configuration management is "sqlite.h.in".
** The makefile makes some minor changes to this file (such as inserting
** the version number) and changes its name to "sqlite3.h" as
** part of the build process.
*/
#ifndef SQLITE3_H
#define SQLITE3_H
#include <stdarg.h>     /* Needed for the definition of va_list */

/*
** Make sure we can call this stuff from C++.
*/
#ifdef __cplusplus
extern "C" {
#endif


    /*
    ** Provide the ability to override linkage features of the interface.
    */
#ifndef SQLITE_EXTERN
# define SQLITE_EXTERN extern
#endif
#ifndef SQLITE_API
# define SQLITE_API
#endif
#ifndef SQLITE_CDECL
# define SQLITE_CDECL
#endif
#ifndef SQLITE_APICALL
# define SQLITE_APICALL
#endif
#ifndef SQLITE_STDCALL
# define SQLITE_STDCALL SQLITE_APICALL
#endif
#ifndef SQLITE_CALLBACK
# define SQLITE_CALLBACK
#endif
#ifndef SQLITE_SYSAPI
# define SQLITE_SYSAPI
#endif

    /*
    ** These no-op macros are used in front of interfaces to mark those
    ** interfaces as either deprecated or experimental.  New applications
    ** should not use deprecated interfaces - they are supported for backwards
    ** compatibility only.  Application writers should be aware that
    ** experimental interfaces are subject to change in point releases.
    **
    ** These macros used to resolve to various kinds of compiler magic that
    ** would generate warning messages when they were used.  But that
    ** compiler magic ended up generating such a flurry of bug reports
    ** that we have taken it all out and gone back to using simple
    ** noop macros.
    */
#define SQLITE_DEPRECATED
#define SQLITE_EXPERIMENTAL

    /*
    ** Ensure these symbols were not defined by some previous header file.
    */
#ifdef SQLITE_VERSION
# undef SQLITE_VERSION
#endif
#ifdef SQLITE_VERSION_NUMBER
# undef SQLITE_VERSION_NUMBER
#endif

    /*
    ** CAPI3REF: Compile-Time Library Version Numbers
    **
    ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
    ** evaluates to a string literal that is the SQLite version in the
    ** format "X.Y.Z" where X is the major version number (always 3 for
    ** SQLite3) and Y is the minor version number and Z is the release number.)^
    ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
    ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
    ** numbers used in [SQLITE_VERSION].)^
    ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
    ** be larger than the release from which it is derived.  Either Y will
    ** be held constant and Z will be incremented or else Y will be incremented
    ** and Z will be reset to zero.
    **
    ** Since [version 3.6.18] ([dateof:3.6.18]),
    ** SQLite source code has been stored in the
    ** <a href="http://www.fossil-scm.org/">Fossil configuration management
    ** system</a>.  ^The SQLITE_SOURCE_ID macro evaluates to
    ** a string which identifies a particular check-in of SQLite
    ** within its configuration management system.  ^The SQLITE_SOURCE_ID
    ** string contains the date and time of the check-in (UTC) and a SHA1
    ** or SHA3-256 hash of the entire source tree.  If the source code has
    ** been edited in any way since it was last checked in, then the last
    ** four hexadecimal digits of the hash may be modified.
    **
    ** See also: [sqlite3_libversion()],
    ** [sqlite3_libversion_number()], [sqlite3_sourceid()],
    ** [sqlite_version()] and [sqlite_source_id()].
    */
#define SQLITE_VERSION        "3.35.5"
#define SQLITE_VERSION_NUMBER 3035005
#define SQLITE_SOURCE_ID      "2021-04-19 18:32:05 1b256d97b553a9611efca188a3d995a2fff712759044ba480f9a0c9e98fae886"

    /*
    ** CAPI3REF: Run-Time Library Version Numbers
    ** KEYWORDS: sqlite3_version sqlite3_sourceid
    **
    ** These interfaces provide the same information as the [SQLITE_VERSION],
    ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
    ** but are associated with the library instead of the header file.  ^(Cautious
    ** programmers might include assert() statements in their application to
    ** verify that values returned by these interfaces match the macros in
    ** the header, and thus ensure that the application is
    ** compiled with matching library and header files.
    **
    ** <blockquote><pre>
    ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
    ** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 );
    ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
    ** </pre></blockquote>)^
    **
    ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
    ** macro.  ^The sqlite3_libversion() function returns a pointer to the
    ** to the sqlite3_version[] string constant.  The sqlite3_libversion()
    ** function is provided for use in DLLs since DLL users usually do not have
    ** direct access to string constants within the DLL.  ^The
    ** sqlite3_libversion_number() function returns an integer equal to
    ** [SQLITE_VERSION_NUMBER].  ^(The sqlite3_sourceid() function returns
    ** a pointer to a string constant whose value is the same as the
    ** [SQLITE_SOURCE_ID] C preprocessor macro.  Except if SQLite is built
    ** using an edited copy of [the amalgamation], then the last four characters
    ** of the hash might be different from [SQLITE_SOURCE_ID].)^
    **
    ** See also: [sqlite_version()] and [sqlite_source_id()].
    */
    SQLITE_API SQLITE_EXTERN const char sqlite3_version[];
    SQLITE_API const char* sqlite3_libversion(void);
    SQLITE_API const char* sqlite3_sourceid(void);
    SQLITE_API int sqlite3_libversion_number(void);

    /*
    ** CAPI3REF: Run-Time Library Compilation Options Diagnostics
    **
    ** ^The sqlite3_compileoption_used() function returns 0 or 1
    ** indicating whether the specified option was defined at
    ** compile time.  ^The SQLITE_ prefix may be omitted from the
    ** option name passed to sqlite3_compileoption_used().
    **
    ** ^The sqlite3_compileoption_get() function allows iterating
    ** over the list of options that were defined at compile time by
    ** returning the N-th compile time option string.  ^If N is out of range,
    ** sqlite3_compileoption_get() returns a NULL pointer.  ^The SQLITE_
    ** prefix is omitted from any strings returned by
    ** sqlite3_compileoption_get().
    **
    ** ^Support for the diagnostic functions sqlite3_compileoption_used()
    ** and sqlite3_compileoption_get() may be omitted by specifying the
    ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
    **
    ** See also: SQL functions [sqlite_compileoption_used()] and
    ** [sqlite_compileoption_get()] and the [compile_options pragma].
    */
#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
    SQLITE_API int sqlite3_compileoption_used(const char* zOptName);
    SQLITE_API const char* sqlite3_compileoption_get(int N);
#else
# define sqlite3_compileoption_used(X) 0
# define sqlite3_compileoption_get(X)  ((void*)0)
#endif

    /*
    ** CAPI3REF: Test To See If The Library Is Threadsafe
    **
    ** ^The sqlite3_threadsafe() function returns zero if and only if
    ** SQLite was compiled with mutexing code omitted due to the
    ** [SQLITE_THREADSAFE] compile-time option being set to 0.
    **
    ** SQLite can be compiled with or without mutexes.  When
    ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
    ** are enabled and SQLite is threadsafe.  When the
    ** [SQLITE_THREADSAFE] macro is 0,
    ** the mutexes are omitted.  Without the mutexes, it is not safe
    ** to use SQLite concurrently from more than one thread.
    **
    ** Enabling mutexes incurs a measurable performance penalty.
    ** So if speed is of utmost importance, it makes sense to disable
    ** the mutexes.  But for maximum safety, mutexes should be enabled.
    ** ^The default behavior is for mutexes to be enabled.
    **
    ** This interface can be used by an application to make sure that the
    ** version of SQLite that it is linking against was compiled with
    ** the desired setting of the [SQLITE_THREADSAFE] macro.
    **
    ** This interface only reports on the compile-time mutex setting
    ** of the [SQLITE_THREADSAFE] flag.  If SQLite is compiled with
    ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
    ** can be fully or partially disabled using a call to [sqlite3_config()]
    ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
    ** or [SQLITE_CONFIG_SERIALIZED].  ^(The return value of the
    ** sqlite3_threadsafe() function shows only the compile-time setting of
    ** thread safety, not any run-time changes to that setting made by
    ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
    ** is unchanged by calls to sqlite3_config().)^
    **
    ** See the [threading mode] documentation for additional information.
    */
    SQLITE_API int sqlite3_threadsafe(void);

    /*
    ** CAPI3REF: Database Connection Handle
    ** KEYWORDS: {database connection} {database connections}
    **
    ** Each open SQLite database is represented by a pointer to an instance of
    ** the opaque structure named "sqlite3".  It is useful to think of an sqlite3
    ** pointer as an object.  The [sqlite3_open()], [sqlite3_open16()], and
    ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
    ** and [sqlite3_close_v2()] are its destructors.  There are many other
    ** interfaces (such as
    ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
    ** [sqlite3_busy_timeout()] to name but three) that are methods on an
    ** sqlite3 object.
    */
    typedef struct sqlite3 sqlite3;

    /*
    ** CAPI3REF: 64-Bit Integer Types
    ** KEYWORDS: sqlite_int64 sqlite_uint64
    **
    ** Because there is no cross-platform way to specify 64-bit integer types
    ** SQLite includes typedefs for 64-bit signed and unsigned integers.
    **
    ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
    ** The sqlite_int64 and sqlite_uint64 types are supported for backwards
    ** compatibility only.
    **
    ** ^The sqlite3_int64 and sqlite_int64 types can store integer values
    ** between -9223372036854775808 and +9223372036854775807 inclusive.  ^The
    ** sqlite3_uint64 and sqlite_uint64 types can store integer values
    ** between 0 and +18446744073709551615 inclusive.
    */
#ifdef SQLITE_INT64_TYPE
    typedef SQLITE_INT64_TYPE sqlite_int64;
# ifdef SQLITE_UINT64_TYPE
    typedef SQLITE_UINT64_TYPE sqlite_uint64;
# else
    typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
# endif
#elif defined(_MSC_VER) || defined(__BORLANDC__)
    typedef __int64 sqlite_int64;
    typedef unsigned __int64 sqlite_uint64;
#else
    typedef long long int sqlite_int64;
    typedef unsigned long long int sqlite_uint64;
#endif
    typedef sqlite_int64 sqlite3_int64;
    typedef sqlite_uint64 sqlite3_uint64;

    /*
    ** If compiling for a processor that lacks floating point support,
    ** substitute integer for floating-point.
    */
#ifdef SQLITE_OMIT_FLOATING_POINT
# define double sqlite3_int64
#endif

    /*
    ** CAPI3REF: Closing A Database Connection
    ** DESTRUCTOR: sqlite3
    **
    ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
    ** for the [sqlite3] object.
    ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
    ** the [sqlite3] object is successfully destroyed and all associated
    ** resources are deallocated.
    **
    ** Ideally, applications should [sqlite3_finalize | finalize] all
    ** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and
    ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
    ** with the [sqlite3] object prior to attempting to close the object.
    ** ^If the database connection is associated with unfinalized prepared
    ** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then
    ** sqlite3_close() will leave the database connection open and return
    ** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared
    ** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups,
    ** it returns [SQLITE_OK] regardless, but instead of deallocating the database
    ** connection immediately, it marks the database connection as an unusable
    ** "zombie" and makes arrangements to automatically deallocate the database
    ** connection after all prepared statements are finalized, all BLOB handles
    ** are closed, and all backups have finished. The sqlite3_close_v2() interface
    ** is intended for use with host languages that are garbage collected, and
    ** where the order in which destructors are called is arbitrary.
    **
    ** ^If an [sqlite3] object is destroyed while a transaction is open,
    ** the transaction is automatically rolled back.
    **
    ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
    ** must be either a NULL
    ** pointer or an [sqlite3] object pointer obtained
    ** from [sqlite3_open()], [sqlite3_open16()], or
    ** [sqlite3_open_v2()], and not previously closed.
    ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
    ** argument is a harmless no-op.
    */
    SQLITE_API int sqlite3_close(sqlite3*);
    SQLITE_API int sqlite3_close_v2(sqlite3*);

    /*
    ** The type for a callback function.
    ** This is legacy and deprecated.  It is included for historical
    ** compatibility and is not documented.
    */
    typedef int (*sqlite3_callback)(void*, int, char**, char**);

    /*
    ** CAPI3REF: One-Step Query Execution Interface
    ** METHOD: sqlite3
    **
    ** The sqlite3_exec() interface is a convenience wrapper around
    ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
    ** that allows an application to run multiple statements of SQL
    ** without having to use a lot of C code.
    **
    ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
    ** semicolon-separate SQL statements passed into its 2nd argument,
    ** in the context of the [database connection] passed in as its 1st
    ** argument.  ^If the callback function of the 3rd argument to
    ** sqlite3_exec() is not NULL, then it is invoked for each result row
    ** coming out of the evaluated SQL statements.  ^The 4th argument to
    ** sqlite3_exec() is relayed through to the 1st argument of each
    ** callback invocation.  ^If the callback pointer to sqlite3_exec()
    ** is NULL, then no callback is ever invoked and result rows are
    ** ignored.
    **
    ** ^If an error occurs while evaluating the SQL statements passed into
    ** sqlite3_exec(), then execution of the current statement stops and
    ** subsequent statements are skipped.  ^If the 5th parameter to sqlite3_exec()
    ** is not NULL then any error message is written into memory obtained
    ** from [sqlite3_malloc()] and passed back through the 5th parameter.
    ** To avoid memory leaks, the application should invoke [sqlite3_free()]
    ** on error message strings returned through the 5th parameter of
    ** sqlite3_exec() after the error message string is no longer needed.
    ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
    ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
    ** NULL before returning.
    **
    ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
    ** routine returns SQLITE_ABORT without invoking the callback again and
    ** without running any subsequent SQL statements.
    **
    ** ^The 2nd argument to the sqlite3_exec() callback function is the
    ** number of columns in the result.  ^The 3rd argument to the sqlite3_exec()
    ** callback is an array of pointers to strings obtained as if from
    ** [sqlite3_column_text()], one for each column.  ^If an element of a
    ** result row is NULL then the corresponding string pointer for the
    ** sqlite3_exec() callback is a NULL pointer.  ^The 4th argument to the
    ** sqlite3_exec() callback is an array of pointers to strings where each
    ** entry represents the name of corresponding result column as obtained
    ** from [sqlite3_column_name()].
    **
    ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
    ** to an empty string, or a pointer that contains only whitespace and/or
    ** SQL comments, then no SQL statements are evaluated and the database
    ** is not changed.
    **
    ** Restrictions:
    **
    ** <ul>
    ** <li> The application must ensure that the 1st parameter to sqlite3_exec()
    **      is a valid and open [database connection].
    ** <li> The application must not close the [database connection] specified by
    **      the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
    ** <li> The application must not modify the SQL statement text passed into
    **      the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
    ** </ul>
    */
    SQLITE_API int sqlite3_exec(
        sqlite3*,                                  /* An open database */
        const char* sql,                           /* SQL to be evaluated */
        int (*callback)(void*, int, char**, char**),  /* Callback function */
        void*,                                    /* 1st argument to callback */
        char** errmsg                              /* Error msg written here */
    );

    /*
    ** CAPI3REF: Result Codes
    ** KEYWORDS: {result code definitions}
    **
    ** Many SQLite functions return an integer result code from the set shown
    ** here in order to indicate success or failure.
    **
    ** New error codes may be added in future versions of SQLite.
    **
    ** See also: [extended result code definitions]
    */
#define SQLITE_OK           0   /* Successful result */
    /* beginning-of-error-codes */
#define SQLITE_ERROR        1   /* Generic error */
#define SQLITE_INTERNAL     2   /* Internal logic error in SQLite */
#define SQLITE_PERM         3   /* Access permission denied */
#define SQLITE_ABORT        4   /* Callback routine requested an abort */
#define SQLITE_BUSY         5   /* The database file is locked */
#define SQLITE_LOCKED       6   /* A table in the database is locked */
#define SQLITE_NOMEM        7   /* A malloc() failed */
#define SQLITE_READONLY     8   /* Attempt to write a readonly database */
#define SQLITE_INTERRUPT    9   /* Operation terminated by sqlite3_interrupt()*/
#define SQLITE_IOERR       10   /* Some kind of disk I/O error occurred */
#define SQLITE_CORRUPT     11   /* The database disk image is malformed */
#define SQLITE_NOTFOUND    12   /* Unknown opcode in sqlite3_file_control() */
#define SQLITE_FULL        13   /* Insertion failed because database is full */
#define SQLITE_CANTOPEN    14   /* Unable to open the database file */
#define SQLITE_PROTOCOL    15   /* Database lock protocol error */
#define SQLITE_EMPTY       16   /* Internal use only */
#define SQLITE_SCHEMA      17   /* The database schema changed */
#define SQLITE_TOOBIG      18   /* String or BLOB exceeds size limit */
#define SQLITE_CONSTRAINT  19   /* Abort due to constraint violation */
#define SQLITE_MISMATCH    20   /* Data type mismatch */
#define SQLITE_MISUSE      21   /* Library used incorrectly */
#define SQLITE_NOLFS       22   /* Uses OS features not supported on host */
#define SQLITE_AUTH        23   /* Authorization denied */
#define SQLITE_FORMAT      24   /* Not used */
#define SQLITE_RANGE       25   /* 2nd parameter to sqlite3_bind out of range */
#define SQLITE_NOTADB      26   /* File opened that is not a database file */
#define SQLITE_NOTICE      27   /* Notifications from sqlite3_log() */
#define SQLITE_WARNING     28   /* Warnings from sqlite3_log() */
#define SQLITE_ROW         100  /* sqlite3_step() has another row ready */
#define SQLITE_DONE        101  /* sqlite3_step() has finished executing */
/* end-of-error-codes */

/*
** CAPI3REF: Extended Result Codes
** KEYWORDS: {extended result code definitions}
**
** In its default configuration, SQLite API routines return one of 30 integer
** [result codes].  However, experience has shown that many of
** these result codes are too coarse-grained.  They do not provide as
** much information about problems as programmers might like.  In an effort to
** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8]
** and later) include
** support for additional result codes that provide more detailed information
** about errors. These [extended result codes] are enabled or disabled
** on a per database connection basis using the
** [sqlite3_extended_result_codes()] API.  Or, the extended code for
** the most recent error can be obtained using
** [sqlite3_extended_errcode()].
*/
#define SQLITE_ERROR_MISSING_COLLSEQ   (SQLITE_ERROR | (1<<8))
#define SQLITE_ERROR_RETRY             (SQLITE_ERROR | (2<<8))
#define SQLITE_ERROR_SNAPSHOT          (SQLITE_ERROR | (3<<8))
#define SQLITE_IOERR_READ              (SQLITE_IOERR | (1<<8))
#define SQLITE_IOERR_SHORT_READ        (SQLITE_IOERR | (2<<8))
#define SQLITE_IOERR_WRITE             (SQLITE_IOERR | (3<<8))
#define SQLITE_IOERR_FSYNC             (SQLITE_IOERR | (4<<8))
#define SQLITE_IOERR_DIR_FSYNC         (SQLITE_IOERR | (5<<8))
#define SQLITE_IOERR_TRUNCATE          (SQLITE_IOERR | (6<<8))
#define SQLITE_IOERR_FSTAT             (SQLITE_IOERR | (7<<8))
#define SQLITE_IOERR_UNLOCK            (SQLITE_IOERR | (8<<8))
#define SQLITE_IOERR_RDLOCK            (SQLITE_IOERR | (9<<8))
#define SQLITE_IOERR_DELETE            (SQLITE_IOERR | (10<<8))
#define SQLITE_IOERR_BLOCKED           (SQLITE_IOERR | (11<<8))
#define SQLITE_IOERR_NOMEM             (SQLITE_IOERR | (12<<8))
#define SQLITE_IOERR_ACCESS            (SQLITE_IOERR | (13<<8))
#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
#define SQLITE_IOERR_LOCK              (SQLITE_IOERR | (15<<8))
#define SQLITE_IOERR_CLOSE             (SQLITE_IOERR | (16<<8))
#define SQLITE_IOERR_DIR_CLOSE         (SQLITE_IOERR | (17<<8))
#define SQLITE_IOERR_SHMOPEN           (SQLITE_IOERR | (18<<8))
#define SQLITE_IOERR_SHMSIZE           (SQLITE_IOERR | (19<<8))
#define SQLITE_IOERR_SHMLOCK           (SQLITE_IOERR | (20<<8))
#define SQLITE_IOERR_SHMMAP            (SQLITE_IOERR | (21<<8))
#define SQLITE_IOERR_SEEK              (SQLITE_IOERR | (22<<8))
#define SQLITE_IOERR_DELETE_NOENT      (SQLITE_IOERR | (23<<8))
#define SQLITE_IOERR_MMAP              (SQLITE_IOERR | (24<<8))
#define SQLITE_IOERR_GETTEMPPATH       (SQLITE_IOERR | (25<<8))
#define SQLITE_IOERR_CONVPATH          (SQLITE_IOERR | (26<<8))
#define SQLITE_IOERR_VNODE             (SQLITE_IOERR | (27<<8))
#define SQLITE_IOERR_AUTH              (SQLITE_IOERR | (28<<8))
#define SQLITE_IOERR_BEGIN_ATOMIC      (SQLITE_IOERR | (29<<8))
#define SQLITE_IOERR_COMMIT_ATOMIC     (SQLITE_IOERR | (30<<8))
#define SQLITE_IOERR_ROLLBACK_ATOMIC   (SQLITE_IOERR | (31<<8))
#define SQLITE_IOERR_DATA              (SQLITE_IOERR | (32<<8))
#define SQLITE_IOERR_CORRUPTFS         (SQLITE_IOERR | (33<<8))
#define SQLITE_LOCKED_SHAREDCACHE      (SQLITE_LOCKED |  (1<<8))
#define SQLITE_LOCKED_VTAB             (SQLITE_LOCKED |  (2<<8))
#define SQLITE_BUSY_RECOVERY           (SQLITE_BUSY   |  (1<<8))
#define SQLITE_BUSY_SNAPSHOT           (SQLITE_BUSY   |  (2<<8))
#define SQLITE_BUSY_TIMEOUT            (SQLITE_BUSY   |  (3<<8))
#define SQLITE_CANTOPEN_NOTEMPDIR      (SQLITE_CANTOPEN | (1<<8))
#define SQLITE_CANTOPEN_ISDIR          (SQLITE_CANTOPEN | (2<<8))
#define SQLITE_CANTOPEN_FULLPATH       (SQLITE_CANTOPEN | (3<<8))
#define SQLITE_CANTOPEN_CONVPATH       (SQLITE_CANTOPEN | (4<<8))
#define SQLITE_CANTOPEN_DIRTYWAL       (SQLITE_CANTOPEN | (5<<8)) /* Not Used */
#define SQLITE_CANTOPEN_SYMLINK        (SQLITE_CANTOPEN | (6<<8))
#define SQLITE_CORRUPT_VTAB            (SQLITE_CORRUPT | (1<<8))
#define SQLITE_CORRUPT_SEQUENCE        (SQLITE_CORRUPT | (2<<8))
#define SQLITE_CORRUPT_INDEX           (SQLITE_CORRUPT | (3<<8))
#define SQLITE_READONLY_RECOVERY       (SQLITE_READONLY | (1<<8))
#define SQLITE_READONLY_CANTLOCK       (SQLITE_READONLY | (2<<8))
#define SQLITE_READONLY_ROLLBACK       (SQLITE_READONLY | (3<<8))
#define SQLITE_READONLY_DBMOVED        (SQLITE_READONLY | (4<<8))
#define SQLITE_READONLY_CANTINIT       (SQLITE_READONLY | (5<<8))
#define SQLITE_READONLY_DIRECTORY      (SQLITE_READONLY | (6<<8))
#define SQLITE_ABORT_ROLLBACK          (SQLITE_ABORT | (2<<8))
#define SQLITE_CONSTRAINT_CHECK        (SQLITE_CONSTRAINT | (1<<8))
#define SQLITE_CONSTRAINT_COMMITHOOK   (SQLITE_CONSTRAINT | (2<<8))
#define SQLITE_CONSTRAINT_FOREIGNKEY   (SQLITE_CONSTRAINT | (3<<8))
#define SQLITE_CONSTRAINT_FUNCTION     (SQLITE_CONSTRAINT | (4<<8))
#define SQLITE_CONSTRAINT_NOTNULL      (SQLITE_CONSTRAINT | (5<<8))
#define SQLITE_CONSTRAINT_PRIMARYKEY   (SQLITE_CONSTRAINT | (6<<8))
#define SQLITE_CONSTRAINT_TRIGGER      (SQLITE_CONSTRAINT | (7<<8))
#define SQLITE_CONSTRAINT_UNIQUE       (SQLITE_CONSTRAINT | (8<<8))
#define SQLITE_CONSTRAINT_VTAB         (SQLITE_CONSTRAINT | (9<<8))
#define SQLITE_CONSTRAINT_ROWID        (SQLITE_CONSTRAINT |(10<<8))
#define SQLITE_CONSTRAINT_PINNED       (SQLITE_CONSTRAINT |(11<<8))
#define SQLITE_NOTICE_RECOVER_WAL      (SQLITE_NOTICE | (1<<8))
#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
#define SQLITE_WARNING_AUTOINDEX       (SQLITE_WARNING | (1<<8))
#define SQLITE_AUTH_USER               (SQLITE_AUTH | (1<<8))
#define SQLITE_OK_LOAD_PERMANENTLY     (SQLITE_OK | (1<<8))
#define SQLITE_OK_SYMLINK              (SQLITE_OK | (2<<8))

/*
** CAPI3REF: Flags For File Open Operations
**
** These bit values are intended for use in the
** 3rd parameter to the [sqlite3_open_v2()] interface and
** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
*/
#define SQLITE_OPEN_READONLY         0x00000001  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_READWRITE        0x00000002  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_CREATE           0x00000004  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_DELETEONCLOSE    0x00000008  /* VFS only */
#define SQLITE_OPEN_EXCLUSIVE        0x00000010  /* VFS only */
#define SQLITE_OPEN_AUTOPROXY        0x00000020  /* VFS only */
#define SQLITE_OPEN_URI              0x00000040  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_MEMORY           0x00000080  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_MAIN_DB          0x00000100  /* VFS only */
#define SQLITE_OPEN_TEMP_DB          0x00000200  /* VFS only */
#define SQLITE_OPEN_TRANSIENT_DB     0x00000400  /* VFS only */
#define SQLITE_OPEN_MAIN_JOURNAL     0x00000800  /* VFS only */
#define SQLITE_OPEN_TEMP_JOURNAL     0x00001000  /* VFS only */
#define SQLITE_OPEN_SUBJOURNAL       0x00002000  /* VFS only */
#define SQLITE_OPEN_SUPER_JOURNAL    0x00004000  /* VFS only */
#define SQLITE_OPEN_NOMUTEX          0x00008000  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_FULLMUTEX        0x00010000  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_SHAREDCACHE      0x00020000  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_PRIVATECACHE     0x00040000  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_WAL              0x00080000  /* VFS only */
#define SQLITE_OPEN_NOFOLLOW         0x01000000  /* Ok for sqlite3_open_v2() */

/* Reserved:                         0x00F00000 */
/* Legacy compatibility: */
#define SQLITE_OPEN_MASTER_JOURNAL   0x00004000  /* VFS only */


/*
** CAPI3REF: Device Characteristics
**
** The xDeviceCharacteristics method of the [sqlite3_io_methods]
** object returns an integer which is a vector of these
** bit values expressing I/O characteristics of the mass storage
** device that holds the file that the [sqlite3_io_methods]
** refers to.
**
** The SQLITE_IOCAP_ATOMIC property means that all writes of
** any size are atomic.  The SQLITE_IOCAP_ATOMICnnn values
** mean that writes of blocks that are nnn bytes in size and
** are aligned to an address which is an integer multiple of
** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means
** that when data is appended to a file, the data is appended
** first then the size of the file is extended, never the other
** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that
** information is written to disk in the same order as calls
** to xWrite().  The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
** after reboot following a crash or power loss, the only bytes in a
** file that were written at the application level might have changed
** and that adjacent bytes, even bytes within the same sector are
** guaranteed to be unchanged.  The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
** flag indicates that a file cannot be deleted when open.  The
** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
** read-only media and cannot be changed even by processes with
** elevated privileges.
**
** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying
** filesystem supports doing multiple write operations atomically when those
** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and
** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE].
*/
#define SQLITE_IOCAP_ATOMIC                 0x00000001
#define SQLITE_IOCAP_ATOMIC512              0x00000002
#define SQLITE_IOCAP_ATOMIC1K               0x00000004
#define SQLITE_IOCAP_ATOMIC2K               0x00000008
#define SQLITE_IOCAP_ATOMIC4K               0x00000010
#define SQLITE_IOCAP_ATOMIC8K               0x00000020
#define SQLITE_IOCAP_ATOMIC16K              0x00000040
#define SQLITE_IOCAP_ATOMIC32K              0x00000080
#define SQLITE_IOCAP_ATOMIC64K              0x00000100
#define SQLITE_IOCAP_SAFE_APPEND            0x00000200
#define SQLITE_IOCAP_SEQUENTIAL             0x00000400
#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN  0x00000800
#define SQLITE_IOCAP_POWERSAFE_OVERWRITE    0x00001000
#define SQLITE_IOCAP_IMMUTABLE              0x00002000
#define SQLITE_IOCAP_BATCH_ATOMIC           0x00004000

/*
** CAPI3REF: File Locking Levels
**
** SQLite uses one of these integer values as the second
** argument to calls it makes to the xLock() and xUnlock() methods
** of an [sqlite3_io_methods] object.
*/
#define SQLITE_LOCK_NONE          0
#define SQLITE_LOCK_SHARED        1
#define SQLITE_LOCK_RESERVED      2
#define SQLITE_LOCK_PENDING       3
#define SQLITE_LOCK_EXCLUSIVE     4

/*
** CAPI3REF: Synchronization Type Flags
**
** When SQLite invokes the xSync() method of an
** [sqlite3_io_methods] object it uses a combination of
** these integer values as the second argument.
**
** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
** sync operation only needs to flush data to mass storage.  Inode
** information need not be flushed. If the lower four bits of the flag
** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
** If the lower four bits equal SQLITE_SYNC_FULL, that means
** to use Mac OS X style fullsync instead of fsync().
**
** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
** settings.  The [synchronous pragma] determines when calls to the
** xSync VFS method occur and applies uniformly across all platforms.
** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
** energetic or rigorous or forceful the sync operations are and
** only make a difference on Mac OSX for the default SQLite code.
** (Third-party VFS implementations might also make the distinction
** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
** operating systems natively supported by SQLite, only Mac OSX
** cares about the difference.)
*/
#define SQLITE_SYNC_NORMAL        0x00002
#define SQLITE_SYNC_FULL          0x00003
#define SQLITE_SYNC_DATAONLY      0x00010

/*
** CAPI3REF: OS Interface Open File Handle
**
** An [sqlite3_file] object represents an open file in the
** [sqlite3_vfs | OS interface layer].  Individual OS interface
** implementations will
** want to subclass this object by appending additional fields
** for their own use.  The pMethods entry is a pointer to an
** [sqlite3_io_methods] object that defines methods for performing
** I/O operations on the open file.
*/
    typedef struct sqlite3_file sqlite3_file;
    struct sqlite3_file {
        const struct sqlite3_io_methods* pMethods;  /* Methods for an open file */
    };

    /*
    ** CAPI3REF: OS Interface File Virtual Methods Object
    **
    ** Every file opened by the [sqlite3_vfs.xOpen] method populates an
    ** [sqlite3_file] object (or, more commonly, a subclass of the
    ** [sqlite3_file] object) with a pointer to an instance of this object.
    ** This object defines the methods used to perform various operations
    ** against the open file represented by the [sqlite3_file] object.
    **
    ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
    ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
    ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed.  The
    ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
    ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
    ** to NULL.
    **
    ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
    ** [SQLITE_SYNC_FULL].  The first choice is the normal fsync().
    ** The second choice is a Mac OS X style fullsync.  The [SQLITE_SYNC_DATAONLY]
    ** flag may be ORed in to indicate that only the data of the file
    ** and not its inode needs to be synced.
    **
    ** The integer values to xLock() and xUnlock() are one of
    ** <ul>
    ** <li> [SQLITE_LOCK_NONE],
    ** <li> [SQLITE_LOCK_SHARED],
    ** <li> [SQLITE_LOCK_RESERVED],
    ** <li> [SQLITE_LOCK_PENDING], or
    ** <li> [SQLITE_LOCK_EXCLUSIVE].
    ** </ul>
    ** xLock() increases the lock. xUnlock() decreases the lock.
    ** The xCheckReservedLock() method checks whether any database connection,
    ** either in this process or in some other process, is holding a RESERVED,
    ** PENDING, or EXCLUSIVE lock on the file.  It returns true
    ** if such a lock exists and false otherwise.
    **
    ** The xFileControl() method is a generic interface that allows custom
    ** VFS implementations to directly control an open file using the
    ** [sqlite3_file_control()] interface.  The second "op" argument is an
    ** integer opcode.  The third argument is a generic pointer intended to
    ** point to a structure that may contain arguments or space in which to
    ** write return values.  Potential uses for xFileControl() might be
    ** functions to enable blocking locks with timeouts, to change the
    ** locking strategy (for example to use dot-file locks), to inquire
    ** about the status of a lock, or to break stale locks.  The SQLite
    ** core reserves all opcodes less than 100 for its own use.
    ** A [file control opcodes | list of opcodes] less than 100 is available.
    ** Applications that define a custom xFileControl method should use opcodes
    ** greater than 100 to avoid conflicts.  VFS implementations should
    ** return [SQLITE_NOTFOUND] for file control opcodes that they do not
    ** recognize.
    **
    ** The xSectorSize() method returns the sector size of the
    ** device that underlies the file.  The sector size is the
    ** minimum write that can be performed without disturbing
    ** other bytes in the file.  The xDeviceCharacteristics()
    ** method returns a bit vector describing behaviors of the
    ** underlying device:
    **
    ** <ul>
    ** <li> [SQLITE_IOCAP_ATOMIC]
    ** <li> [SQLITE_IOCAP_ATOMIC512]
    ** <li> [SQLITE_IOCAP_ATOMIC1K]
    ** <li> [SQLITE_IOCAP_ATOMIC2K]
    ** <li> [SQLITE_IOCAP_ATOMIC4K]
    ** <li> [SQLITE_IOCAP_ATOMIC8K]
    ** <li> [SQLITE_IOCAP_ATOMIC16K]
    ** <li> [SQLITE_IOCAP_ATOMIC32K]
    ** <li> [SQLITE_IOCAP_ATOMIC64K]
    ** <li> [SQLITE_IOCAP_SAFE_APPEND]
    ** <li> [SQLITE_IOCAP_SEQUENTIAL]
    ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN]
    ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE]
    ** <li> [SQLITE_IOCAP_IMMUTABLE]
    ** <li> [SQLITE_IOCAP_BATCH_ATOMIC]
    ** </ul>
    **
    ** The SQLITE_IOCAP_ATOMIC property means that all writes of
    ** any size are atomic.  The SQLITE_IOCAP_ATOMICnnn values
    ** mean that writes of blocks that are nnn bytes in size and
    ** are aligned to an address which is an integer multiple of
    ** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means
    ** that when data is appended to a file, the data is appended
    ** first then the size of the file is extended, never the other
    ** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that
    ** information is written to disk in the same order as calls
    ** to xWrite().
    **
    ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
    ** in the unread portions of the buffer with zeros.  A VFS that
    ** fails to zero-fill short reads might seem to work.  However,
    ** failure to zero-fill short reads will eventually lead to
    ** database corruption.
    */
    typedef struct sqlite3_io_methods sqlite3_io_methods;
    struct sqlite3_io_methods {
        int iVersion;
        int (*xClose)(sqlite3_file*);
        int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
        int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
        int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
        int (*xSync)(sqlite3_file*, int flags);
        int (*xFileSize)(sqlite3_file*, sqlite3_int64* pSize);
        int (*xLock)(sqlite3_file*, int);
        int (*xUnlock)(sqlite3_file*, int);
        int (*xCheckReservedLock)(sqlite3_file*, int* pResOut);
        int (*xFileControl)(sqlite3_file*, int op, void* pArg);
        int (*xSectorSize)(sqlite3_file*);
        int (*xDeviceCharacteristics)(sqlite3_file*);
        /* Methods above are valid for version 1 */
        int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
        int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
        void (*xShmBarrier)(sqlite3_file*);
        int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
        /* Methods above are valid for version 2 */
        int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void** pp);
        int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void* p);
        /* Methods above are valid for version 3 */
        /* Additional methods may be added in future releases */
    };

    /*
    ** CAPI3REF: Standard File Control Opcodes
    ** KEYWORDS: {file control opcodes} {file control opcode}
    **
    ** These integer constants are opcodes for the xFileControl method
    ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
    ** interface.
    **
    ** <ul>
    ** <li>[[SQLITE_FCNTL_LOCKSTATE]]
    ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging.  This
    ** opcode causes the xFileControl method to write the current state of
    ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
    ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
    ** into an integer that the pArg argument points to. This capability
    ** is used during testing and is only available when the SQLITE_TEST
    ** compile-time option is used.
    **
    ** <li>[[SQLITE_FCNTL_SIZE_HINT]]
    ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
    ** layer a hint of how large the database file will grow to be during the
    ** current transaction.  This hint is not guaranteed to be accurate but it
    ** is often close.  The underlying VFS might choose to preallocate database
    ** file space based on this hint in order to help writes to the database
    ** file run faster.
    **
    ** <li>[[SQLITE_FCNTL_SIZE_LIMIT]]
    ** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that
    ** implements [sqlite3_deserialize()] to set an upper bound on the size
    ** of the in-memory database.  The argument is a pointer to a [sqlite3_int64].
    ** If the integer pointed to is negative, then it is filled in with the
    ** current limit.  Otherwise the limit is set to the larger of the value
    ** of the integer pointed to and the current database size.  The integer
    ** pointed to is set to the new limit.
    **
    ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
    ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
    ** extends and truncates the database file in chunks of a size specified
    ** by the user. The fourth argument to [sqlite3_file_control()] should
    ** point to an integer (type int) containing the new chunk-size to use
    ** for the nominated database. Allocating database file space in large
    ** chunks (say 1MB at a time), may reduce file-system fragmentation and
    ** improve performance on some systems.
    **
    ** <li>[[SQLITE_FCNTL_FILE_POINTER]]
    ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
    ** to the [sqlite3_file] object associated with a particular database
    ** connection.  See also [SQLITE_FCNTL_JOURNAL_POINTER].
    **
    ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]]
    ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer
    ** to the [sqlite3_file] object associated with the journal file (either
    ** the [rollback journal] or the [write-ahead log]) for a particular database
    ** connection.  See also [SQLITE_FCNTL_FILE_POINTER].
    **
    ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
    ** No longer in use.
    **
    ** <li>[[SQLITE_FCNTL_SYNC]]
    ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
    ** sent to the VFS immediately before the xSync method is invoked on a
    ** database file descriptor. Or, if the xSync method is not invoked
    ** because the user has configured SQLite with
    ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
    ** of the xSync method. In most cases, the pointer argument passed with
    ** this file-control is NULL. However, if the database file is being synced
    ** as part of a multi-database commit, the argument points to a nul-terminated
    ** string containing the transactions super-journal file name. VFSes that
    ** do not need this signal should silently ignore this opcode. Applications
    ** should not call [sqlite3_file_control()] with this opcode as doing so may
    ** disrupt the operation of the specialized VFSes that do require it.
    **
    ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
    ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
    ** and sent to the VFS after a transaction has been committed immediately
    ** but before the database is unlocked. VFSes that do not need this signal
    ** should silently ignore this opcode. Applications should not call
    ** [sqlite3_file_control()] with this opcode as doing so may disrupt the
    ** operation of the specialized VFSes that do require it.
    **
    ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
    ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
    ** retry counts and intervals for certain disk I/O operations for the
    ** windows [VFS] in order to provide robustness in the presence of
    ** anti-virus programs.  By default, the windows VFS will retry file read,
    ** file write, and file delete operations up to 10 times, with a delay
    ** of 25 milliseconds before the first retry and with the delay increasing
    ** by an additional 25 milliseconds with each subsequent retry.  This
    ** opcode allows these two values (10 retries and 25 milliseconds of delay)
    ** to be adjusted.  The values are changed for all database connections
    ** within the same process.  The argument is a pointer to an array of two
    ** integers where the first integer is the new retry count and the second
    ** integer is the delay.  If either integer is negative, then the setting
    ** is not changed but instead the prior value of that setting is written
    ** into the array entry, allowing the current retry settings to be
    ** interrogated.  The zDbName parameter is ignored.
    **
    ** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
    ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
    ** persistent [WAL | Write Ahead Log] setting.  By default, the auxiliary
    ** write ahead log ([WAL file]) and shared memory
    ** files used for transaction control
    ** are automatically deleted when the latest connection to the database
    ** closes.  Setting persistent WAL mode causes those files to persist after
    ** close.  Persisting the files is useful when other processes that do not
    ** have write permission on the directory containing the database file want
    ** to read the database file, as the WAL and shared memory files must exist
    ** in order for the database to be readable.  The fourth parameter to
    ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
    ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
    ** WAL mode.  If the integer is -1, then it is overwritten with the current
    ** WAL persistence setting.
    **
    ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
    ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
    ** persistent "powersafe-overwrite" or "PSOW" setting.  The PSOW setting
    ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
    ** xDeviceCharacteristics methods. The fourth parameter to
    ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
    ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
    ** mode.  If the integer is -1, then it is overwritten with the current
    ** zero-damage mode setting.
    **
    ** <li>[[SQLITE_FCNTL_OVERWRITE]]
    ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
    ** a write transaction to indicate that, unless it is rolled back for some
    ** reason, the entire database file will be overwritten by the current
    ** transaction. This is used by VACUUM operations.
    **
    ** <li>[[SQLITE_FCNTL_VFSNAME]]
    ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
    ** all [VFSes] in the VFS stack.  The names are of all VFS shims and the
    ** final bottom-level VFS are written into memory obtained from
    ** [sqlite3_malloc()] and the result is stored in the char* variable
    ** that the fourth parameter of [sqlite3_file_control()] points to.
    ** The caller is responsible for freeing the memory when done.  As with
    ** all file-control actions, there is no guarantee that this will actually
    ** do anything.  Callers should initialize the char* variable to a NULL
    ** pointer in case this file-control is not implemented.  This file-control
    ** is intended for diagnostic use only.
    **
    ** <li>[[SQLITE_FCNTL_VFS_POINTER]]
    ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level
    ** [VFSes] currently in use.  ^(The argument X in
    ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be
    ** of type "[sqlite3_vfs] **".  This opcodes will set *X
    ** to a pointer to the top-level VFS.)^
    ** ^When there are multiple VFS shims in the stack, this opcode finds the
    ** upper-most shim only.
    **
    ** <li>[[SQLITE_FCNTL_PRAGMA]]
    ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
    ** file control is sent to the open [sqlite3_file] object corresponding
    ** to the database file to which the pragma statement refers. ^The argument
    ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
    ** pointers to strings (char**) in which the second element of the array
    ** is the name of the pragma and the third element is the argument to the
    ** pragma or NULL if the pragma has no argument.  ^The handler for an
    ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
    ** of the char** argument point to a string obtained from [sqlite3_mprintf()]
    ** or the equivalent and that string will become the result of the pragma or
    ** the error message if the pragma fails. ^If the
    ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
    ** [PRAGMA] processing continues.  ^If the [SQLITE_FCNTL_PRAGMA]
    ** file control returns [SQLITE_OK], then the parser assumes that the
    ** VFS has handled the PRAGMA itself and the parser generates a no-op
    ** prepared statement if result string is NULL, or that returns a copy
    ** of the result string if the string is non-NULL.
    ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
    ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
    ** that the VFS encountered an error while handling the [PRAGMA] and the
    ** compilation of the PRAGMA fails with an error.  ^The [SQLITE_FCNTL_PRAGMA]
    ** file control occurs at the beginning of pragma statement analysis and so
    ** it is able to override built-in [PRAGMA] statements.
    **
    ** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
    ** ^The [SQLITE_FCNTL_BUSYHANDLER]
    ** file-control may be invoked by SQLite on the database file handle
    ** shortly after it is opened in order to provide a custom VFS with access
    ** to the connection's busy-handler callback. The argument is of type (void**)
    ** - an array of two (void *) values. The first (void *) actually points
    ** to a function of type (int (*)(void *)). In order to invoke the connection's
    ** busy-handler, this function should be invoked with the second (void *) in
    ** the array as the only argument. If it returns non-zero, then the operation
    ** should be retried. If it returns zero, the custom VFS should abandon the
    ** current operation.
    **
    ** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
    ** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
    ** to have SQLite generate a
    ** temporary filename using the same algorithm that is followed to generate
    ** temporary filenames for TEMP tables and other internal uses.  The
    ** argument should be a char** which will be filled with the filename
    ** written into memory obtained from [sqlite3_malloc()].  The caller should
    ** invoke [sqlite3_free()] on the result to avoid a memory leak.
    **
    ** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
    ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
    ** maximum number of bytes that will be used for memory-mapped I/O.
    ** The argument is a pointer to a value of type sqlite3_int64 that
    ** is an advisory maximum number of bytes in the file to memory map.  The
    ** pointer is overwritten with the old value.  The limit is not changed if
    ** the value originally pointed to is negative, and so the current limit
    ** can be queried by passing in a pointer to a negative number.  This
    ** file-control is used internally to implement [PRAGMA mmap_size].
    **
    ** <li>[[SQLITE_FCNTL_TRACE]]
    ** The [SQLITE_FCNTL_TRACE] file control provides advisory information
    ** to the VFS about what the higher layers of the SQLite stack are doing.
    ** This file control is used by some VFS activity tracing [shims].
    ** The argument is a zero-terminated string.  Higher layers in the
    ** SQLite stack may generate instances of this file control if
    ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
    **
    ** <li>[[SQLITE_FCNTL_HAS_MOVED]]
    ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
    ** pointer to an integer and it writes a boolean into that integer depending
    ** on whether or not the file has been renamed, moved, or deleted since it
    ** was first opened.
    **
    ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]]
    ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the
    ** underlying native file handle associated with a file handle.  This file
    ** control interprets its argument as a pointer to a native file handle and
    ** writes the resulting value there.
    **
    ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
    ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging.  This
    ** opcode causes the xFileControl method to swap the file handle with the one
    ** pointed to by the pArg argument.  This capability is used during testing
    ** and only needs to be supported when SQLITE_TEST is defined.
    **
    ** <li>[[SQLITE_FCNTL_WAL_BLOCK]]
    ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
    ** be advantageous to block on the next WAL lock if the lock is not immediately
    ** available.  The WAL subsystem issues this signal during rare
    ** circumstances in order to fix a problem with priority inversion.
    ** Applications should <em>not</em> use this file-control.
    **
    ** <li>[[SQLITE_FCNTL_ZIPVFS]]
    ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
    ** VFS should return SQLITE_NOTFOUND for this opcode.
    **
    ** <li>[[SQLITE_FCNTL_RBU]]
    ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
    ** the RBU extension only.  All other VFS should return SQLITE_NOTFOUND for
    ** this opcode.
    **
    ** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]]
    ** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then
    ** the file descriptor is placed in "batch write mode", which
    ** means all subsequent write operations will be deferred and done
    ** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE].  Systems
    ** that do not support batch atomic writes will return SQLITE_NOTFOUND.
    ** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to
    ** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or
    ** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make
    ** no VFS interface calls on the same [sqlite3_file] file descriptor
    ** except for calls to the xWrite method and the xFileControl method
    ** with [SQLITE_FCNTL_SIZE_HINT].
    **
    ** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]]
    ** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write
    ** operations since the previous successful call to
    ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically.
    ** This file control returns [SQLITE_OK] if and only if the writes were
    ** all performed successfully and have been committed to persistent storage.
    ** ^Regardless of whether or not it is successful, this file control takes
    ** the file descriptor out of batch write mode so that all subsequent
    ** write operations are independent.
    ** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without
    ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
    **
    ** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]]
    ** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write
    ** operations since the previous successful call to
    ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back.
    ** ^This file control takes the file descriptor out of batch write mode
    ** so that all subsequent write operations are independent.
    ** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without
    ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
    **
    ** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]]
    ** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS
    ** to block for up to M milliseconds before failing when attempting to
    ** obtain a file lock using the xLock or xShmLock methods of the VFS.
    ** The parameter is a pointer to a 32-bit signed integer that contains
    ** the value that M is to be set to. Before returning, the 32-bit signed
    ** integer is overwritten with the previous value of M.
    **
    ** <li>[[SQLITE_FCNTL_DATA_VERSION]]
    ** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to
    ** a database file.  The argument is a pointer to a 32-bit unsigned integer.
    ** The "data version" for the pager is written into the pointer.  The
    ** "data version" changes whenever any change occurs to the corresponding
    ** database file, either through SQL statements on the same database
    ** connection or through transactions committed by separate database
    ** connections possibly in other processes. The [sqlite3_total_changes()]
    ** interface can be used to find if any database on the connection has changed,
    ** but that interface responds to changes on TEMP as well as MAIN and does
    ** not provide a mechanism to detect changes to MAIN only.  Also, the
    ** [sqlite3_total_changes()] interface responds to internal changes only and
    ** omits changes made by other database connections.  The
    ** [PRAGMA data_version] command provides a mechanism to detect changes to
    ** a single attached database that occur due to other database connections,
    ** but omits changes implemented by the database connection on which it is
    ** called.  This file control is the only mechanism to detect changes that
    ** happen either internally or externally and that are associated with
    ** a particular attached database.
    **
    ** <li>[[SQLITE_FCNTL_CKPT_START]]
    ** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint
    ** in wal mode before the client starts to copy pages from the wal
    ** file to the database file.
    **
    ** <li>[[SQLITE_FCNTL_CKPT_DONE]]
    ** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint
    ** in wal mode after the client has finished copying pages from the wal
    ** file to the database file, but before the *-shm file is updated to
    ** record the fact that the pages have been checkpointed.
    ** </ul>
    */
#define SQLITE_FCNTL_LOCKSTATE               1
#define SQLITE_FCNTL_GET_LOCKPROXYFILE       2
#define SQLITE_FCNTL_SET_LOCKPROXYFILE       3
#define SQLITE_FCNTL_LAST_ERRNO              4
#define SQLITE_FCNTL_SIZE_HINT               5
#define SQLITE_FCNTL_CHUNK_SIZE              6
#define SQLITE_FCNTL_FILE_POINTER            7
#define SQLITE_FCNTL_SYNC_OMITTED            8
#define SQLITE_FCNTL_WIN32_AV_RETRY          9
#define SQLITE_FCNTL_PERSIST_WAL            10
#define SQLITE_FCNTL_OVERWRITE              11
#define SQLITE_FCNTL_VFSNAME                12
#define SQLITE_FCNTL_POWERSAFE_OVERWRITE    13
#define SQLITE_FCNTL_PRAGMA                 14
#define SQLITE_FCNTL_BUSYHANDLER            15
#define SQLITE_FCNTL_TEMPFILENAME           16
#define SQLITE_FCNTL_MMAP_SIZE              18
#define SQLITE_FCNTL_TRACE                  19
#define SQLITE_FCNTL_HAS_MOVED              20
#define SQLITE_FCNTL_SYNC                   21
#define SQLITE_FCNTL_COMMIT_PHASETWO        22
#define SQLITE_FCNTL_WIN32_SET_HANDLE       23
#define SQLITE_FCNTL_WAL_BLOCK              24
#define SQLITE_FCNTL_ZIPVFS                 25
#define SQLITE_FCNTL_RBU                    26
#define SQLITE_FCNTL_VFS_POINTER            27
#define SQLITE_FCNTL_JOURNAL_POINTER        28
#define SQLITE_FCNTL_WIN32_GET_HANDLE       29
#define SQLITE_FCNTL_PDB                    30
#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE     31
#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE    32
#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE  33
#define SQLITE_FCNTL_LOCK_TIMEOUT           34
#define SQLITE_FCNTL_DATA_VERSION           35
#define SQLITE_FCNTL_SIZE_LIMIT             36
#define SQLITE_FCNTL_CKPT_DONE              37
#define SQLITE_FCNTL_RESERVE_BYTES          38
#define SQLITE_FCNTL_CKPT_START             39

    /* deprecated names */
#define SQLITE_GET_LOCKPROXYFILE      SQLITE_FCNTL_GET_LOCKPROXYFILE
#define SQLITE_SET_LOCKPROXYFILE      SQLITE_FCNTL_SET_LOCKPROXYFILE
#define SQLITE_LAST_ERRNO             SQLITE_FCNTL_LAST_ERRNO


/*
** CAPI3REF: Mutex Handle
**
** The mutex module within SQLite defines [sqlite3_mutex] to be an
** abstract type for a mutex object.  The SQLite core never looks
** at the internal representation of an [sqlite3_mutex].  It only
** deals with pointers to the [sqlite3_mutex] object.
**
** Mutexes are created using [sqlite3_mutex_alloc()].
*/
    typedef struct sqlite3_mutex sqlite3_mutex;

    /*
    ** CAPI3REF: Loadable Extension Thunk
    **
    ** A pointer to the opaque sqlite3_api_routines structure is passed as
    ** the third parameter to entry points of [loadable extensions].  This
    ** structure must be typedefed in order to work around compiler warnings
    ** on some platforms.
    */
    typedef struct sqlite3_api_routines sqlite3_api_routines;

    /*
    ** CAPI3REF: OS Interface Object
    **
    ** An instance of the sqlite3_vfs object defines the interface between
    ** the SQLite core and the underlying operating system.  The "vfs"
    ** in the name of the object stands for "virtual file system".  See
    ** the [VFS | VFS documentation] for further information.
    **
    ** The VFS interface is sometimes extended by adding new methods onto
    ** the end.  Each time such an extension occurs, the iVersion field
    ** is incremented.  The iVersion value started out as 1 in
    ** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2
    ** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased
    ** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6].  Additional fields
    ** may be appended to the sqlite3_vfs object and the iVersion value
    ** may increase again in future versions of SQLite.
    ** Note that due to an oversight, the structure
    ** of the sqlite3_vfs object changed in the transition from
    ** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0]
    ** and yet the iVersion field was not increased.
    **
    ** The szOsFile field is the size of the subclassed [sqlite3_file]
    ** structure used by this VFS.  mxPathname is the maximum length of
    ** a pathname in this VFS.
    **
    ** Registered sqlite3_vfs objects are kept on a linked list formed by
    ** the pNext pointer.  The [sqlite3_vfs_register()]
    ** and [sqlite3_vfs_unregister()] interfaces manage this list
    ** in a thread-safe way.  The [sqlite3_vfs_find()] interface
    ** searches the list.  Neither the application code nor the VFS
    ** implementation should use the pNext pointer.
    **
    ** The pNext field is the only field in the sqlite3_vfs
    ** structure that SQLite will ever modify.  SQLite will only access
    ** or modify this field while holding a particular static mutex.
    ** The application should never modify anything within the sqlite3_vfs
    ** object once the object has been registered.
    **
    ** The zName field holds the name of the VFS module.  The name must
    ** be unique across all VFS modules.
    **
    ** [[sqlite3_vfs.xOpen]]
    ** ^SQLite guarantees that the zFilename parameter to xOpen
    ** is either a NULL pointer or string obtained
    ** from xFullPathname() with an optional suffix added.
    ** ^If a suffix is added to the zFilename parameter, it will
    ** consist of a single "-" character followed by no more than
    ** 11 alphanumeric and/or "-" characters.
    ** ^SQLite further guarantees that
    ** the string will be valid and unchanged until xClose() is
    ** called. Because of the previous sentence,
    ** the [sqlite3_file] can safely store a pointer to the
    ** filename if it needs to remember the filename for some reason.
    ** If the zFilename parameter to xOpen is a NULL pointer then xOpen
    ** must invent its own temporary name for the file.  ^Whenever the
    ** xFilename parameter is NULL it will also be the case that the
    ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
    **
    ** The flags argument to xOpen() includes all bits set in
    ** the flags argument to [sqlite3_open_v2()].  Or if [sqlite3_open()]
    ** or [sqlite3_open16()] is used, then flags includes at least
    ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
    ** If xOpen() opens a file read-only then it sets *pOutFlags to
    ** include [SQLITE_OPEN_READONLY].  Other bits in *pOutFlags may be set.
    **
    ** ^(SQLite will also add one of the following flags to the xOpen()
    ** call, depending on the object being opened:
    **
    ** <ul>
    ** <li>  [SQLITE_OPEN_MAIN_DB]
    ** <li>  [SQLITE_OPEN_MAIN_JOURNAL]
    ** <li>  [SQLITE_OPEN_TEMP_DB]
    ** <li>  [SQLITE_OPEN_TEMP_JOURNAL]
    ** <li>  [SQLITE_OPEN_TRANSIENT_DB]
    ** <li>  [SQLITE_OPEN_SUBJOURNAL]
    ** <li>  [SQLITE_OPEN_SUPER_JOURNAL]
    ** <li>  [SQLITE_OPEN_WAL]
    ** </ul>)^
    **
    ** The file I/O implementation can use the object type flags to
    ** change the way it deals with files.  For example, an application
    ** that does not care about crash recovery or rollback might make
    ** the open of a journal file a no-op.  Writes to this journal would
    ** also be no-ops, and any attempt to read the journal would return
    ** SQLITE_IOERR.  Or the implementation might recognize that a database
    ** file will be doing page-aligned sector reads and writes in a random
    ** order and set up its I/O subsystem accordingly.
    **
    ** SQLite might also add one of the following flags to the xOpen method:
    **
    ** <ul>
    ** <li> [SQLITE_OPEN_DELETEONCLOSE]
    ** <li> [SQLITE_OPEN_EXCLUSIVE]
    ** </ul>
    **
    ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
    ** deleted when it is closed.  ^The [SQLITE_OPEN_DELETEONCLOSE]
    ** will be set for TEMP databases and their journals, transient
    ** databases, and subjournals.
    **
    ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
    ** with the [SQLITE_OPEN_CREATE] flag, which are both directly
    ** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
    ** API.  The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
    ** SQLITE_OPEN_CREATE, is used to indicate that file should always
    ** be created, and that it is an error if it already exists.
    ** It is <i>not</i> used to indicate the file should be opened
    ** for exclusive access.
    **
    ** ^At least szOsFile bytes of memory are allocated by SQLite
    ** to hold the [sqlite3_file] structure passed as the third
    ** argument to xOpen.  The xOpen method does not have to
    ** allocate the structure; it should just fill it in.  Note that
    ** the xOpen method must set the sqlite3_file.pMethods to either
    ** a valid [sqlite3_io_methods] object or to NULL.  xOpen must do
    ** this even if the open fails.  SQLite expects that the sqlite3_file.pMethods
    ** element will be valid after xOpen returns regardless of the success
    ** or failure of the xOpen call.
    **
    ** [[sqlite3_vfs.xAccess]]
    ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
    ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
    ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
    ** to test whether a file is at least readable.  The SQLITE_ACCESS_READ
    ** flag is never actually used and is not implemented in the built-in
    ** VFSes of SQLite.  The file is named by the second argument and can be a
    ** directory. The xAccess method returns [SQLITE_OK] on success or some
    ** non-zero error code if there is an I/O error or if the name of
    ** the file given in the second argument is illegal.  If SQLITE_OK
    ** is returned, then non-zero or zero is written into *pResOut to indicate
    ** whether or not the file is accessible.
    **
    ** ^SQLite will always allocate at least mxPathname+1 bytes for the
    ** output buffer xFullPathname.  The exact size of the output buffer
    ** is also passed as a parameter to both  methods. If the output buffer
    ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
    ** handled as a fatal error by SQLite, vfs implementations should endeavor
    ** to prevent this by setting mxPathname to a sufficiently large value.
    **
    ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
    ** interfaces are not strictly a part of the filesystem, but they are
    ** included in the VFS structure for completeness.
    ** The xRandomness() function attempts to return nBytes bytes
    ** of good-quality randomness into zOut.  The return value is
    ** the actual number of bytes of randomness obtained.
    ** The xSleep() method causes the calling thread to sleep for at
    ** least the number of microseconds given.  ^The xCurrentTime()
    ** method returns a Julian Day Number for the current date and time as
    ** a floating point value.
    ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
    ** Day Number multiplied by 86400000 (the number of milliseconds in
    ** a 24-hour day).
    ** ^SQLite will use the xCurrentTimeInt64() method to get the current
    ** date and time if that method is available (if iVersion is 2 or
    ** greater and the function pointer is not NULL) and will fall back
    ** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
    **
    ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
    ** are not used by the SQLite core.  These optional interfaces are provided
    ** by some VFSes to facilitate testing of the VFS code. By overriding
    ** system calls with functions under its control, a test program can
    ** simulate faults and error conditions that would otherwise be difficult
    ** or impossible to induce.  The set of system calls that can be overridden
    ** varies from one VFS to another, and from one version of the same VFS to the
    ** next.  Applications that use these interfaces must be prepared for any
    ** or all of these interfaces to be NULL or for their behavior to change
    ** from one release to the next.  Applications must not attempt to access
    ** any of these methods if the iVersion of the VFS is less than 3.
    */
    typedef struct sqlite3_vfs sqlite3_vfs;
    typedef void (*sqlite3_syscall_ptr)(void);
    struct sqlite3_vfs {
        int iVersion;            /* Structure version number (currently 3) */
        int szOsFile;            /* Size of subclassed sqlite3_file */
        int mxPathname;          /* Maximum file pathname length */
        sqlite3_vfs* pNext;      /* Next registered VFS */
        const char* zName;       /* Name of this virtual file system */
        void* pAppData;          /* Pointer to application-specific data */
        int (*xOpen)(sqlite3_vfs*, const char* zName, sqlite3_file*,
            int flags, int* pOutFlags);
        int (*xDelete)(sqlite3_vfs*, const char* zName, int syncDir);
        int (*xAccess)(sqlite3_vfs*, const char* zName, int flags, int* pResOut);
        int (*xFullPathname)(sqlite3_vfs*, const char* zName, int nOut, char* zOut);
        void* (*xDlOpen)(sqlite3_vfs*, const char* zFilename);
        void (*xDlError)(sqlite3_vfs*, int nByte, char* zErrMsg);
        void (*(*xDlSym)(sqlite3_vfs*, void*, const char* zSymbol))(void);
        void (*xDlClose)(sqlite3_vfs*, void*);
        int (*xRandomness)(sqlite3_vfs*, int nByte, char* zOut);
        int (*xSleep)(sqlite3_vfs*, int microseconds);
        int (*xCurrentTime)(sqlite3_vfs*, double*);
        int (*xGetLastError)(sqlite3_vfs*, int, char*);
        /*
        ** The methods above are in version 1 of the sqlite_vfs object
        ** definition.  Those that follow are added in version 2 or later
        */
        int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
        /*
        ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
        ** Those below are for version 3 and greater.
        */
        int (*xSetSystemCall)(sqlite3_vfs*, const char* zName, sqlite3_syscall_ptr);
        sqlite3_syscall_ptr(*xGetSystemCall)(sqlite3_vfs*, const char* zName);
        const char* (*xNextSystemCall)(sqlite3_vfs*, const char* zName);
        /*
        ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
        ** New fields may be appended in future versions.  The iVersion
        ** value will increment whenever this happens.
        */
    };

    /*
    ** CAPI3REF: Flags for the xAccess VFS method
    **
    ** These integer constants can be used as the third parameter to
    ** the xAccess method of an [sqlite3_vfs] object.  They determine
    ** what kind of permissions the xAccess method is looking for.
    ** With SQLITE_ACCESS_EXISTS, the xAccess method
    ** simply checks whether the file exists.
    ** With SQLITE_ACCESS_READWRITE, the xAccess method
    ** checks whether the named directory is both readable and writable
    ** (in other words, if files can be added, removed, and renamed within
    ** the directory).
    ** The SQLITE_ACCESS_READWRITE constant is currently used only by the
    ** [temp_store_directory pragma], though this could change in a future
    ** release of SQLite.
    ** With SQLITE_ACCESS_READ, the xAccess method
    ** checks whether the file is readable.  The SQLITE_ACCESS_READ constant is
    ** currently unused, though it might be used in a future release of
    ** SQLite.
    */
#define SQLITE_ACCESS_EXISTS    0
#define SQLITE_ACCESS_READWRITE 1   /* Used by PRAGMA temp_store_directory */
#define SQLITE_ACCESS_READ      2   /* Unused */

    /*
    ** CAPI3REF: Flags for the xShmLock VFS method
    **
    ** These integer constants define the various locking operations
    ** allowed by the xShmLock method of [sqlite3_io_methods].  The
    ** following are the only legal combinations of flags to the
    ** xShmLock method:
    **
    ** <ul>
    ** <li>  SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
    ** <li>  SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
    ** <li>  SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
    ** <li>  SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
    ** </ul>
    **
    ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
    ** was given on the corresponding lock.
    **
    ** The xShmLock method can transition between unlocked and SHARED or
    ** between unlocked and EXCLUSIVE.  It cannot transition between SHARED
    ** and EXCLUSIVE.
    */
#define SQLITE_SHM_UNLOCK       1
#define SQLITE_SHM_LOCK         2
#define SQLITE_SHM_SHARED       4
#define SQLITE_SHM_EXCLUSIVE    8

    /*
    ** CAPI3REF: Maximum xShmLock index
    **
    ** The xShmLock method on [sqlite3_io_methods] may use values
    ** between 0 and this upper bound as its "offset" argument.
    ** The SQLite core will never attempt to acquire or release a
    ** lock outside of this range
    */
#define SQLITE_SHM_NLOCK        8


    /*
    ** CAPI3REF: Initialize The SQLite Library
    **
    ** ^The sqlite3_initialize() routine initializes the
    ** SQLite library.  ^The sqlite3_shutdown() routine
    ** deallocates any resources that were allocated by sqlite3_initialize().
    ** These routines are designed to aid in process initialization and
    ** shutdown on embedded systems.  Workstation applications using
    ** SQLite normally do not need to invoke either of these routines.
    **
    ** A call to sqlite3_initialize() is an "effective" call if it is
    ** the first time sqlite3_initialize() is invoked during the lifetime of
    ** the process, or if it is the first time sqlite3_initialize() is invoked
    ** following a call to sqlite3_shutdown().  ^(Only an effective call
    ** of sqlite3_initialize() does any initialization.  All other calls
    ** are harmless no-ops.)^
    **
    ** A call to sqlite3_shutdown() is an "effective" call if it is the first
    ** call to sqlite3_shutdown() since the last sqlite3_initialize().  ^(Only
    ** an effective call to sqlite3_shutdown() does any deinitialization.
    ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
    **
    ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
    ** is not.  The sqlite3_shutdown() interface must only be called from a
    ** single thread.  All open [database connections] must be closed and all
    ** other SQLite resources must be deallocated prior to invoking
    ** sqlite3_shutdown().
    **
    ** Among other things, ^sqlite3_initialize() will invoke
    ** sqlite3_os_init().  Similarly, ^sqlite3_shutdown()
    ** will invoke sqlite3_os_end().
    **
    ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
    ** ^If for some reason, sqlite3_initialize() is unable to initialize
    ** the library (perhaps it is unable to allocate a needed resource such
    ** as a mutex) it returns an [error code] other than [SQLITE_OK].
    **
    ** ^The sqlite3_initialize() routine is called internally by many other
    ** SQLite interfaces so that an application usually does not need to
    ** invoke sqlite3_initialize() directly.  For example, [sqlite3_open()]
    ** calls sqlite3_initialize() so the SQLite library will be automatically
    ** initialized when [sqlite3_open()] is called if it has not be initialized
    ** already.  ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
    ** compile-time option, then the automatic calls to sqlite3_initialize()
    ** are omitted and the application must call sqlite3_initialize() directly
    ** prior to using any other SQLite interface.  For maximum portability,
    ** it is recommended that applications always invoke sqlite3_initialize()
    ** directly prior to using any other SQLite interface.  Future releases
    ** of SQLite may require this.  In other words, the behavior exhibited
    ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
    ** default behavior in some future release of SQLite.
    **
    ** The sqlite3_os_init() routine does operating-system specific
    ** initialization of the SQLite library.  The sqlite3_os_end()
    ** routine undoes the effect of sqlite3_os_init().  Typical tasks
    ** performed by these routines include allocation or deallocation
    ** of static resources, initialization of global variables,
    ** setting up a default [sqlite3_vfs] module, or setting up
    ** a default configuration using [sqlite3_config()].
    **
    ** The application should never invoke either sqlite3_os_init()
    ** or sqlite3_os_end() directly.  The application should only invoke
    ** sqlite3_initialize() and sqlite3_shutdown().  The sqlite3_os_init()
    ** interface is called automatically by sqlite3_initialize() and
    ** sqlite3_os_end() is called by sqlite3_shutdown().  Appropriate
    ** implementations for sqlite3_os_init() and sqlite3_os_end()
    ** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
    ** When [custom builds | built for other platforms]
    ** (using the [SQLITE_OS_OTHER=1] compile-time
    ** option) the application must supply a suitable implementation for
    ** sqlite3_os_init() and sqlite3_os_end().  An application-supplied
    ** implementation of sqlite3_os_init() or sqlite3_os_end()
    ** must return [SQLITE_OK] on success and some other [error code] upon
    ** failure.
    */
    SQLITE_API int sqlite3_initialize(void);
    SQLITE_API int sqlite3_shutdown(void);
    SQLITE_API int sqlite3_os_init(void);
    SQLITE_API int sqlite3_os_end(void);

    /*
    ** CAPI3REF: Configuring The SQLite Library
    **
    ** The sqlite3_config() interface is used to make global configuration
    ** changes to SQLite in order to tune SQLite to the specific needs of
    ** the application.  The default configuration is recommended for most
    ** applications and so this routine is usually not necessary.  It is
    ** provided to support rare applications with unusual needs.
    **
    ** <b>The sqlite3_config() interface is not threadsafe. The application
    ** must ensure that no other SQLite interfaces are invoked by other
    ** threads while sqlite3_config() is running.</b>
    **
    ** The sqlite3_config() interface
    ** may only be invoked prior to library initialization using
    ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
    ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
    ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
    ** Note, however, that ^sqlite3_config() can be called as part of the
    ** implementation of an application-defined [sqlite3_os_init()].
    **
    ** The first argument to sqlite3_config() is an integer
    ** [configuration option] that determines
    ** what property of SQLite is to be configured.  Subsequent arguments
    ** vary depending on the [configuration option]
    ** in the first argument.
    **
    ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
    ** ^If the option is unknown or SQLite is unable to set the option
    ** then this routine returns a non-zero [error code].
    */
    SQLITE_API int sqlite3_config(int, ...);

    /*
    ** CAPI3REF: Configure database connections
    ** METHOD: sqlite3
    **
    ** The sqlite3_db_config() interface is used to make configuration
    ** changes to a [database connection].  The interface is similar to
    ** [sqlite3_config()] except that the changes apply to a single
    ** [database connection] (specified in the first argument).
    **
    ** The second argument to sqlite3_db_config(D,V,...)  is the
    ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
    ** that indicates what aspect of the [database connection] is being configured.
    ** Subsequent arguments vary depending on the configuration verb.
    **
    ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
    ** the call is considered successful.
    */
    SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);

    /*
    ** CAPI3REF: Memory Allocation Routines
    **
    ** An instance of this object defines the interface between SQLite
    ** and low-level memory allocation routines.
    **
    ** This object is used in only one place in the SQLite interface.
    ** A pointer to an instance of this object is the argument to
    ** [sqlite3_config()] when the configuration option is
    ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
    ** By creating an instance of this object
    ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
    ** during configuration, an application can specify an alternative
    ** memory allocation subsystem for SQLite to use for all of its
    ** dynamic memory needs.
    **
    ** Note that SQLite comes with several [built-in memory allocators]
    ** that are perfectly adequate for the overwhelming majority of applications
    ** and that this object is only useful to a tiny minority of applications
    ** with specialized memory allocation requirements.  This object is
    ** also used during testing of SQLite in order to specify an alternative
    ** memory allocator that simulates memory out-of-memory conditions in
    ** order to verify that SQLite recovers gracefully from such
    ** conditions.
    **
    ** The xMalloc, xRealloc, and xFree methods must work like the
    ** malloc(), realloc() and free() functions from the standard C library.
    ** ^SQLite guarantees that the second argument to
    ** xRealloc is always a value returned by a prior call to xRoundup.
    **
    ** xSize should return the allocated size of a memory allocation
    ** previously obtained from xMalloc or xRealloc.  The allocated size
    ** is always at least as big as the requested size but may be larger.
    **
    ** The xRoundup method returns what would be the allocated size of
    ** a memory allocation given a particular requested size.  Most memory
    ** allocators round up memory allocations at least to the next multiple
    ** of 8.  Some allocators round up to a larger multiple or to a power of 2.
    ** Every memory allocation request coming in through [sqlite3_malloc()]
    ** or [sqlite3_realloc()] first calls xRoundup.  If xRoundup returns 0,
    ** that causes the corresponding memory allocation to fail.
    **
    ** The xInit method initializes the memory allocator.  For example,
    ** it might allocate any required mutexes or initialize internal data
    ** structures.  The xShutdown method is invoked (indirectly) by
    ** [sqlite3_shutdown()] and should deallocate any resources acquired
    ** by xInit.  The pAppData pointer is used as the only parameter to
    ** xInit and xShutdown.
    **
    ** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes
    ** the xInit method, so the xInit method need not be threadsafe.  The
    ** xShutdown method is only called from [sqlite3_shutdown()] so it does
    ** not need to be threadsafe either.  For all other methods, SQLite
    ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
    ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
    ** it is by default) and so the methods are automatically serialized.
    ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
    ** methods must be threadsafe or else make their own arrangements for
    ** serialization.
    **
    ** SQLite will never invoke xInit() more than once without an intervening
    ** call to xShutdown().
    */
    typedef struct sqlite3_mem_methods sqlite3_mem_methods;
    struct sqlite3_mem_methods {
        void* (*xMalloc)(int);         /* Memory allocation function */
        void (*xFree)(void*);          /* Free a prior allocation */
        void* (*xRealloc)(void*, int);  /* Resize an allocation */
        int (*xSize)(void*);           /* Return the size of an allocation */
        int (*xRoundup)(int);          /* Round up request size to allocation size */
        int (*xInit)(void*);           /* Initialize the memory allocator */
        void (*xShutdown)(void*);      /* Deinitialize the memory allocator */
        void* pAppData;                /* Argument to xInit() and xShutdown() */
    };

    /*
    ** CAPI3REF: Configuration Options
    ** KEYWORDS: {configuration option}
    **
    ** These constants are the available integer configuration options that
    ** can be passed as the first argument to the [sqlite3_config()] interface.
    **
    ** New configuration options may be added in future releases of SQLite.
    ** Existing configuration options might be discontinued.  Applications
    ** should check the return code from [sqlite3_config()] to make sure that
    ** the call worked.  The [sqlite3_config()] interface will return a
    ** non-zero [error code] if a discontinued or unsupported configuration option
    ** is invoked.
    **
    ** <dl>
    ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
    ** <dd>There are no arguments to this option.  ^This option sets the
    ** [threading mode] to Single-thread.  In other words, it disables
    ** all mutexing and puts SQLite into a mode where it can only be used
    ** by a single thread.   ^If SQLite is compiled with
    ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
    ** it is not possible to change the [threading mode] from its default
    ** value of Single-thread and so [sqlite3_config()] will return
    ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
    ** configuration option.</dd>
    **
    ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
    ** <dd>There are no arguments to this option.  ^This option sets the
    ** [threading mode] to Multi-thread.  In other words, it disables
    ** mutexing on [database connection] and [prepared statement] objects.
    ** The application is responsible for serializing access to
    ** [database connections] and [prepared statements].  But other mutexes
    ** are enabled so that SQLite will be safe to use in a multi-threaded
    ** environment as long as no two threads attempt to use the same
    ** [database connection] at the same time.  ^If SQLite is compiled with
    ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
    ** it is not possible to set the Multi-thread [threading mode] and
    ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
    ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
    **
    ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
    ** <dd>There are no arguments to this option.  ^This option sets the
    ** [threading mode] to Serialized. In other words, this option enables
    ** all mutexes including the recursive
    ** mutexes on [database connection] and [prepared statement] objects.
    ** In this mode (which is the default when SQLite is compiled with
    ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
    ** to [database connections] and [prepared statements] so that the
    ** application is free to use the same [database connection] or the
    ** same [prepared statement] in different threads at the same time.
    ** ^If SQLite is compiled with
    ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
    ** it is not possible to set the Serialized [threading mode] and
    ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
    ** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
    **
    ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
    ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is
    ** a pointer to an instance of the [sqlite3_mem_methods] structure.
    ** The argument specifies
    ** alternative low-level memory allocation routines to be used in place of
    ** the memory allocation routines built into SQLite.)^ ^SQLite makes
    ** its own private copy of the content of the [sqlite3_mem_methods] structure
    ** before the [sqlite3_config()] call returns.</dd>
    **
    ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
    ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
    ** is a pointer to an instance of the [sqlite3_mem_methods] structure.
    ** The [sqlite3_mem_methods]
    ** structure is filled with the currently defined memory allocation routines.)^
    ** This option can be used to overload the default memory allocation
    ** routines with a wrapper that simulations memory allocation failure or
    ** tracks memory usage, for example. </dd>
    **
    ** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt>
    ** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of
    ** type int, interpreted as a boolean, which if true provides a hint to
    ** SQLite that it should avoid large memory allocations if possible.
    ** SQLite will run faster if it is free to make large memory allocations,
    ** but some application might prefer to run slower in exchange for
    ** guarantees about memory fragmentation that are possible if large
    ** allocations are avoided.  This hint is normally off.
    ** </dd>
    **
    ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
    ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int,
    ** interpreted as a boolean, which enables or disables the collection of
    ** memory allocation statistics. ^(When memory allocation statistics are
    ** disabled, the following SQLite interfaces become non-operational:
    **   <ul>
    **   <li> [sqlite3_hard_heap_limit64()]
    **   <li> [sqlite3_memory_used()]
    **   <li> [sqlite3_memory_highwater()]
    **   <li> [sqlite3_soft_heap_limit64()]
    **   <li> [sqlite3_status64()]
    **   </ul>)^
    ** ^Memory allocation statistics are enabled by default unless SQLite is
    ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
    ** allocation statistics are disabled by default.
    ** </dd>
    **
    ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
    ** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used.
    ** </dd>
    **
    ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
    ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool
    ** that SQLite can use for the database page cache with the default page
    ** cache implementation.
    ** This configuration option is a no-op if an application-defined page
    ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].
    ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
    ** 8-byte aligned memory (pMem), the size of each page cache line (sz),
    ** and the number of cache lines (N).
    ** The sz argument should be the size of the largest database page
    ** (a power of two between 512 and 65536) plus some extra bytes for each
    ** page header.  ^The number of extra bytes needed by the page header
    ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].
    ** ^It is harmless, apart from the wasted memory,
    ** for the sz parameter to be larger than necessary.  The pMem
    ** argument must be either a NULL pointer or a pointer to an 8-byte
    ** aligned block of memory of at least sz*N bytes, otherwise
    ** subsequent behavior is undefined.
    ** ^When pMem is not NULL, SQLite will strive to use the memory provided
    ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if
    ** a page cache line is larger than sz bytes or if all of the pMem buffer
    ** is exhausted.
    ** ^If pMem is NULL and N is non-zero, then each database connection
    ** does an initial bulk allocation for page cache memory
    ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or
    ** of -1024*N bytes if N is negative, . ^If additional
    ** page cache memory is needed beyond what is provided by the initial
    ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each
    ** additional cache line. </dd>
    **
    ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
    ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer
    ** that SQLite will use for all of its dynamic memory allocation needs
    ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE].
    ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
    ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
    ** [SQLITE_ERROR] if invoked otherwise.
    ** ^There are three arguments to SQLITE_CONFIG_HEAP:
    ** An 8-byte aligned pointer to the memory,
    ** the number of bytes in the memory buffer, and the minimum allocation size.
    ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
    ** to using its default memory allocator (the system malloc() implementation),
    ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC].  ^If the
    ** memory pointer is not NULL then the alternative memory
    ** allocator is engaged to handle all of SQLites memory allocation needs.
    ** The first pointer (the memory pointer) must be aligned to an 8-byte
    ** boundary or subsequent behavior of SQLite will be undefined.
    ** The minimum allocation size is capped at 2**12. Reasonable values
    ** for the minimum allocation size are 2**5 through 2**8.</dd>
    **
    ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
    ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
    ** pointer to an instance of the [sqlite3_mutex_methods] structure.
    ** The argument specifies alternative low-level mutex routines to be used
    ** in place the mutex routines built into SQLite.)^  ^SQLite makes a copy of
    ** the content of the [sqlite3_mutex_methods] structure before the call to
    ** [sqlite3_config()] returns. ^If SQLite is compiled with
    ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
    ** the entire mutexing subsystem is omitted from the build and hence calls to
    ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
    ** return [SQLITE_ERROR].</dd>
    **
    ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
    ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
    ** is a pointer to an instance of the [sqlite3_mutex_methods] structure.  The
    ** [sqlite3_mutex_methods]
    ** structure is filled with the currently defined mutex routines.)^
    ** This option can be used to overload the default mutex allocation
    ** routines with a wrapper used to track mutex usage for performance
    ** profiling or testing, for example.   ^If SQLite is compiled with
    ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
    ** the entire mutexing subsystem is omitted from the build and hence calls to
    ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
    ** return [SQLITE_ERROR].</dd>
    **
    ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
    ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
    ** the default size of lookaside memory on each [database connection].
    ** The first argument is the
    ** size of each lookaside buffer slot and the second is the number of
    ** slots allocated to each database connection.)^  ^(SQLITE_CONFIG_LOOKASIDE
    ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
    ** option to [sqlite3_db_config()] can be used to change the lookaside
    ** configuration on individual connections.)^ </dd>
    **
    ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
    ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is
    ** a pointer to an [sqlite3_pcache_methods2] object.  This object specifies
    ** the interface to a custom page cache implementation.)^
    ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
    **
    ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
    ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
    ** is a pointer to an [sqlite3_pcache_methods2] object.  SQLite copies of
    ** the current page cache implementation into that object.)^ </dd>
    **
    ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
    ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
    ** global [error log].
    ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
    ** function with a call signature of void(*)(void*,int,const char*),
    ** and a pointer to void. ^If the function pointer is not NULL, it is
    ** invoked by [sqlite3_log()] to process each logging event.  ^If the
    ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
    ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
    ** passed through as the first parameter to the application-defined logger
    ** function whenever that function is invoked.  ^The second parameter to
    ** the logger function is a copy of the first parameter to the corresponding
    ** [sqlite3_log()] call and is intended to be a [result code] or an
    ** [extended result code].  ^The third parameter passed to the logger is
    ** log message after formatting via [sqlite3_snprintf()].
    ** The SQLite logging interface is not reentrant; the logger function
    ** supplied by the application must not invoke any SQLite interface.
    ** In a multi-threaded application, the application-defined logger
    ** function must be threadsafe. </dd>
    **
    ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
    ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
    ** If non-zero, then URI handling is globally enabled. If the parameter is zero,
    ** then URI handling is globally disabled.)^ ^If URI handling is globally
    ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
    ** [sqlite3_open16()] or
    ** specified as part of [ATTACH] commands are interpreted as URIs, regardless
    ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
    ** connection is opened. ^If it is globally disabled, filenames are
    ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
    ** database connection is opened. ^(By default, URI handling is globally
    ** disabled. The default value may be changed by compiling with the
    ** [SQLITE_USE_URI] symbol defined.)^
    **
    ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
    ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
    ** argument which is interpreted as a boolean in order to enable or disable
    ** the use of covering indices for full table scans in the query optimizer.
    ** ^The default setting is determined
    ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
    ** if that compile-time option is omitted.
    ** The ability to disable the use of covering indices for full table scans
    ** is because some incorrectly coded legacy applications might malfunction
    ** when the optimization is enabled.  Providing the ability to
    ** disable the optimization allows the older, buggy application code to work
    ** without change even with newer versions of SQLite.
    **
    ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
    ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
    ** <dd> These options are obsolete and should not be used by new code.
    ** They are retained for backwards compatibility but are now no-ops.
    ** </dd>
    **
    ** [[SQLITE_CONFIG_SQLLOG]]
    ** <dt>SQLITE_CONFIG_SQLLOG
    ** <dd>This option is only available if sqlite is compiled with the
    ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
    ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
    ** The second should be of type (void*). The callback is invoked by the library
    ** in three separate circumstances, identified by the value passed as the
    ** fourth parameter. If the fourth parameter is 0, then the database connection
    ** passed as the second argument has just been opened. The third argument
    ** points to a buffer containing the name of the main database file. If the
    ** fourth parameter is 1, then the SQL statement that the third parameter
    ** points to has just been executed. Or, if the fourth parameter is 2, then
    ** the connection being passed as the second parameter is being closed. The
    ** third parameter is passed NULL In this case.  An example of using this
    ** configuration option can be seen in the "test_sqllog.c" source file in
    ** the canonical SQLite source tree.</dd>
    **
    ** [[SQLITE_CONFIG_MMAP_SIZE]]
    ** <dt>SQLITE_CONFIG_MMAP_SIZE
    ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
    ** that are the default mmap size limit (the default setting for
    ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
    ** ^The default setting can be overridden by each database connection using
    ** either the [PRAGMA mmap_size] command, or by using the
    ** [SQLITE_FCNTL_MMAP_SIZE] file control.  ^(The maximum allowed mmap size
    ** will be silently truncated if necessary so that it does not exceed the
    ** compile-time maximum mmap size set by the
    ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
    ** ^If either argument to this option is negative, then that argument is
    ** changed to its compile-time default.
    **
    ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
    ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
    ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
    ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
    ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
    ** that specifies the maximum size of the created heap.
    **
    ** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
    ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
    ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
    ** is a pointer to an integer and writes into that integer the number of extra
    ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
    ** The amount of extra space required can change depending on the compiler,
    ** target platform, and SQLite version.
    **
    ** [[SQLITE_CONFIG_PMASZ]]
    ** <dt>SQLITE_CONFIG_PMASZ
    ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which
    ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded
    ** sorter to that integer.  The default minimum PMA Size is set by the
    ** [SQLITE_SORTER_PMASZ] compile-time option.  New threads are launched
    ** to help with sort operations when multithreaded sorting
    ** is enabled (using the [PRAGMA threads] command) and the amount of content
    ** to be sorted exceeds the page size times the minimum of the
    ** [PRAGMA cache_size] setting and this value.
    **
    ** [[SQLITE_CONFIG_STMTJRNL_SPILL]]
    ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL
    ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which
    ** becomes the [statement journal] spill-to-disk threshold.
    ** [Statement journals] are held in memory until their size (in bytes)
    ** exceeds this threshold, at which point they are written to disk.
    ** Or if the threshold is -1, statement journals are always held
    ** exclusively in memory.
    ** Since many statement journals never become large, setting the spill
    ** threshold to a value such as 64KiB can greatly reduce the amount of
    ** I/O required to support statement rollback.
    ** The default value for this setting is controlled by the
    ** [SQLITE_STMTJRNL_SPILL] compile-time option.
    **
    ** [[SQLITE_CONFIG_SORTERREF_SIZE]]
    ** <dt>SQLITE_CONFIG_SORTERREF_SIZE
    ** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter
    ** of type (int) - the new value of the sorter-reference size threshold.
    ** Usually, when SQLite uses an external sort to order records according
    ** to an ORDER BY clause, all fields required by the caller are present in the
    ** sorted records. However, if SQLite determines based on the declared type
    ** of a table column that its values are likely to be very large - larger
    ** than the configured sorter-reference size threshold - then a reference
    ** is stored in each sorted record and the required column values loaded
    ** from the database as records are returned in sorted order. The default
    ** value for this option is to never use this optimization. Specifying a
    ** negative value for this option restores the default behaviour.
    ** This option is only available if SQLite is compiled with the
    ** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option.
    **
    ** [[SQLITE_CONFIG_MEMDB_MAXSIZE]]
    ** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE
    ** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter
    ** [sqlite3_int64] parameter which is the default maximum size for an in-memory
    ** database created using [sqlite3_deserialize()].  This default maximum
    ** size can be adjusted up or down for individual databases using the
    ** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control].  If this
    ** configuration setting is never used, then the default maximum is determined
    ** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option.  If that
    ** compile-time option is not set, then the default maximum is 1073741824.
    ** </dl>
    */
#define SQLITE_CONFIG_SINGLETHREAD  1  /* nil */
#define SQLITE_CONFIG_MULTITHREAD   2  /* nil */
#define SQLITE_CONFIG_SERIALIZED    3  /* nil */
#define SQLITE_CONFIG_MALLOC        4  /* sqlite3_mem_methods* */
#define SQLITE_CONFIG_GETMALLOC     5  /* sqlite3_mem_methods* */
#define SQLITE_CONFIG_SCRATCH       6  /* No longer used */
#define SQLITE_CONFIG_PAGECACHE     7  /* void*, int sz, int N */
#define SQLITE_CONFIG_HEAP          8  /* void*, int nByte, int min */
#define SQLITE_CONFIG_MEMSTATUS     9  /* boolean */
#define SQLITE_CONFIG_MUTEX        10  /* sqlite3_mutex_methods* */
#define SQLITE_CONFIG_GETMUTEX     11  /* sqlite3_mutex_methods* */
    /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
#define SQLITE_CONFIG_LOOKASIDE    13  /* int int */
#define SQLITE_CONFIG_PCACHE       14  /* no-op */
#define SQLITE_CONFIG_GETPCACHE    15  /* no-op */
#define SQLITE_CONFIG_LOG          16  /* xFunc, void* */
#define SQLITE_CONFIG_URI          17  /* int */
#define SQLITE_CONFIG_PCACHE2      18  /* sqlite3_pcache_methods2* */
#define SQLITE_CONFIG_GETPCACHE2   19  /* sqlite3_pcache_methods2* */
#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20  /* int */
#define SQLITE_CONFIG_SQLLOG       21  /* xSqllog, void* */
#define SQLITE_CONFIG_MMAP_SIZE    22  /* sqlite3_int64, sqlite3_int64 */
#define SQLITE_CONFIG_WIN32_HEAPSIZE      23  /* int nByte */
#define SQLITE_CONFIG_PCACHE_HDRSZ        24  /* int *psz */
#define SQLITE_CONFIG_PMASZ               25  /* unsigned int szPma */
#define SQLITE_CONFIG_STMTJRNL_SPILL      26  /* int nByte */
#define SQLITE_CONFIG_SMALL_MALLOC        27  /* boolean */
#define SQLITE_CONFIG_SORTERREF_SIZE      28  /* int nByte */
#define SQLITE_CONFIG_MEMDB_MAXSIZE       29  /* sqlite3_int64 */

/*
** CAPI3REF: Database Connection Configuration Options
**
** These constants are the available integer configuration options that
** can be passed as the second argument to the [sqlite3_db_config()] interface.
**
** New configuration options may be added in future releases of SQLite.
** Existing configuration options might be discontinued.  Applications
** should check the return code from [sqlite3_db_config()] to make sure that
** the call worked.  ^The [sqlite3_db_config()] interface will return a
** non-zero [error code] if a discontinued or unsupported configuration option
** is invoked.
**
** <dl>
** [[SQLITE_DBCONFIG_LOOKASIDE]]
** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
** <dd> ^This option takes three additional arguments that determine the
** [lookaside memory allocator] configuration for the [database connection].
** ^The first argument (the third parameter to [sqlite3_db_config()] is a
** pointer to a memory buffer to use for lookaside memory.
** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
** may be NULL in which case SQLite will allocate the
** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
** size of each lookaside buffer slot.  ^The third argument is the number of
** slots.  The size of the buffer in the first argument must be greater than
** or equal to the product of the second and third arguments.  The buffer
** must be aligned to an 8-byte boundary.  ^If the second argument to
** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
** rounded down to the next smaller multiple of 8.  ^(The lookaside memory
** configuration for a database connection can only be changed when that
** connection is not currently using lookaside memory, or in other words
** when the "current value" returned by
** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero.
** Any attempt to change the lookaside memory configuration when lookaside
** memory is in use leaves the configuration unchanged and returns
** [SQLITE_BUSY].)^</dd>
**
** [[SQLITE_DBCONFIG_ENABLE_FKEY]]
** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
** <dd> ^This option is used to enable or disable the enforcement of
** [foreign key constraints].  There should be two additional arguments.
** The first argument is an integer which is 0 to disable FK enforcement,
** positive to enable FK enforcement or negative to leave FK enforcement
** unchanged.  The second parameter is a pointer to an integer into which
** is written 0 or 1 to indicate whether FK enforcement is off or on
** following this call.  The second parameter may be a NULL pointer, in
** which case the FK enforcement setting is not reported back. </dd>
**
** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]]
** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
** There should be two additional arguments.
** The first argument is an integer which is 0 to disable triggers,
** positive to enable triggers or negative to leave the setting unchanged.
** The second parameter is a pointer to an integer into which
** is written 0 or 1 to indicate whether triggers are disabled or enabled
** following this call.  The second parameter may be a NULL pointer, in
** which case the trigger setting is not reported back.
**
** <p>Originally this option disabled all triggers.  ^(However, since
** SQLite version 3.35.0, TEMP triggers are still allowed even if
** this option is off.  So, in other words, this option now only disables
** triggers in the main database schema or in the schemas of ATTACH-ed
** databases.)^ </dd>
**
** [[SQLITE_DBCONFIG_ENABLE_VIEW]]
** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt>
** <dd> ^This option is used to enable or disable [CREATE VIEW | views].
** There should be two additional arguments.
** The first argument is an integer which is 0 to disable views,
** positive to enable views or negative to leave the setting unchanged.
** The second parameter is a pointer to an integer into which
** is written 0 or 1 to indicate whether views are disabled or enabled
** following this call.  The second parameter may be a NULL pointer, in
** which case the view setting is not reported back.
**
** <p>Originally this option disabled all views.  ^(However, since
** SQLite version 3.35.0, TEMP views are still allowed even if
** this option is off.  So, in other words, this option now only disables
** views in the main database schema or in the schemas of ATTACH-ed
** databases.)^ </dd>
**
** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]]
** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt>
** <dd> ^This option is used to enable or disable the
** [fts3_tokenizer()] function which is part of the
** [FTS3] full-text search engine extension.
** There should be two additional arguments.
** The first argument is an integer which is 0 to disable fts3_tokenizer() or
** positive to enable fts3_tokenizer() or negative to leave the setting
** unchanged.
** The second parameter is a pointer to an integer into which
** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled
** following this call.  The second parameter may be a NULL pointer, in
** which case the new setting is not reported back. </dd>
**
** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]]
** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt>
** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()]
** interface independently of the [load_extension()] SQL function.
** The [sqlite3_enable_load_extension()] API enables or disables both the
** C-API [sqlite3_load_extension()] and the SQL function [load_extension()].
** There should be two additional arguments.
** When the first argument to this interface is 1, then only the C-API is
** enabled and the SQL function remains disabled.  If the first argument to
** this interface is 0, then both the C-API and the SQL function are disabled.
** If the first argument is -1, then no changes are made to state of either the
** C-API or the SQL function.
** The second parameter is a pointer to an integer into which
** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface
** is disabled or enabled following this call.  The second parameter may
** be a NULL pointer, in which case the new setting is not reported back.
** </dd>
**
** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt>
** <dd> ^This option is used to change the name of the "main" database
** schema.  ^The sole argument is a pointer to a constant UTF8 string
** which will become the new schema name in place of "main".  ^SQLite
** does not make a copy of the new main schema name string, so the application
** must ensure that the argument passed into this DBCONFIG option is unchanged
** until after the database connection closes.
** </dd>
**
** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]]
** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt>
** <dd> Usually, when a database in wal mode is closed or detached from a
** database handle, SQLite checks if this will mean that there are now no
** connections at all to the database. If so, it performs a checkpoint
** operation before closing the connection. This option may be used to
** override this behaviour. The first parameter passed to this operation
** is an integer - positive to disable checkpoints-on-close, or zero (the
** default) to enable them, and negative to leave the setting unchanged.
** The second parameter is a pointer to an integer
** into which is written 0 or 1 to indicate whether checkpoints-on-close
** have been disabled - 0 if they are not disabled, 1 if they are.
** </dd>
**
** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt>
** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates
** the [query planner stability guarantee] (QPSG).  When the QPSG is active,
** a single SQL query statement will always use the same algorithm regardless
** of values of [bound parameters].)^ The QPSG disables some query optimizations
** that look at the values of bound parameters, which can make some queries
** slower.  But the QPSG has the advantage of more predictable behavior.  With
** the QPSG active, SQLite will always use the same query plan in the field as
** was used during testing in the lab.
** The first argument to this setting is an integer which is 0 to disable
** the QPSG, positive to enable QPSG, or negative to leave the setting
** unchanged. The second parameter is a pointer to an integer into which
** is written 0 or 1 to indicate whether the QPSG is disabled or enabled
** following this call.
** </dd>
**
** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt>
** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not
** include output for any operations performed by trigger programs. This
** option is used to set or clear (the default) a flag that governs this
** behavior. The first parameter passed to this operation is an integer -
** positive to enable output for trigger programs, or zero to disable it,
** or negative to leave the setting unchanged.
** The second parameter is a pointer to an integer into which is written
** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if
** it is not disabled, 1 if it is.
** </dd>
**
** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt>
** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run
** [VACUUM] in order to reset a database back to an empty database
** with no schema and no content. The following process works even for
** a badly corrupted database file:
** <ol>
** <li> If the database connection is newly opened, make sure it has read the
**      database schema by preparing then discarding some query against the
**      database, or calling sqlite3_table_column_metadata(), ignoring any
**      errors.  This step is only necessary if the application desires to keep
**      the database in WAL mode after the reset if it was in WAL mode before
**      the reset.
** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0);
** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0);
** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0);
** </ol>
** Because resetting a database is destructive and irreversible, the
** process requires the use of this obscure API and multiple steps to help
** ensure that it does not happen by accident.
**
** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt>
** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the
** "defensive" flag for a database connection.  When the defensive
** flag is enabled, language features that allow ordinary SQL to
** deliberately corrupt the database file are disabled.  The disabled
** features include but are not limited to the following:
** <ul>
** <li> The [PRAGMA writable_schema=ON] statement.
** <li> The [PRAGMA journal_mode=OFF] statement.
** <li> Writes to the [sqlite_dbpage] virtual table.
** <li> Direct writes to [shadow tables].
** </ul>
** </dd>
**
** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt>
** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the
** "writable_schema" flag. This has the same effect and is logically equivalent
** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF].
** The first argument to this setting is an integer which is 0 to disable
** the writable_schema, positive to enable writable_schema, or negative to
** leave the setting unchanged. The second parameter is a pointer to an
** integer into which is written 0 or 1 to indicate whether the writable_schema
** is enabled or disabled following this call.
** </dd>
**
** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]]
** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt>
** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates
** the legacy behavior of the [ALTER TABLE RENAME] command such it
** behaves as it did prior to [version 3.24.0] (2018-06-04).  See the
** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for
** additional information. This feature can also be turned on and off
** using the [PRAGMA legacy_alter_table] statement.
** </dd>
**
** [[SQLITE_DBCONFIG_DQS_DML]]
** <dt>SQLITE_DBCONFIG_DQS_DML</td>
** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates
** the legacy [double-quoted string literal] misfeature for DML statements
** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The
** default value of this setting is determined by the [-DSQLITE_DQS]
** compile-time option.
** </dd>
**
** [[SQLITE_DBCONFIG_DQS_DDL]]
** <dt>SQLITE_DBCONFIG_DQS_DDL</td>
** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates
** the legacy [double-quoted string literal] misfeature for DDL statements,
** such as CREATE TABLE and CREATE INDEX. The
** default value of this setting is determined by the [-DSQLITE_DQS]
** compile-time option.
** </dd>
**
** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]]
** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</td>
** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to
** assume that database schemas are untainted by malicious content.
** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite
** takes additional defensive steps to protect the application from harm
** including:
** <ul>
** <li> Prohibit the use of SQL functions inside triggers, views,
** CHECK constraints, DEFAULT clauses, expression indexes,
** partial indexes, or generated columns
** unless those functions are tagged with [SQLITE_INNOCUOUS].
** <li> Prohibit the use of virtual tables inside of triggers or views
** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS].
** </ul>
** This setting defaults to "on" for legacy compatibility, however
** all applications are advised to turn it off if possible. This setting
** can also be controlled using the [PRAGMA trusted_schema] statement.
** </dd>
**
** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]]
** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</td>
** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates
** the legacy file format flag.  When activated, this flag causes all newly
** created database file to have a schema format version number (the 4-byte
** integer found at offset 44 into the database header) of 1.  This in turn
** means that the resulting database file will be readable and writable by
** any SQLite version back to 3.0.0 ([dateof:3.0.0]).  Without this setting,
** newly created databases are generally not understandable by SQLite versions
** prior to 3.3.0 ([dateof:3.3.0]).  As these words are written, there
** is now scarcely any need to generated database files that are compatible
** all the way back to version 3.0.0, and so this setting is of little
** practical use, but is provided so that SQLite can continue to claim the
** ability to generate new database files that are compatible with  version
** 3.0.0.
** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on,
** the [VACUUM] command will fail with an obscure error when attempting to
** process a table with generated columns and a descending index.  This is
** not considered a bug since SQLite versions 3.3.0 and earlier do not support
** either generated columns or decending indexes.
** </dd>
** </dl>
*/
#define SQLITE_DBCONFIG_MAINDBNAME            1000 /* const char* */
#define SQLITE_DBCONFIG_LOOKASIDE             1001 /* void* int int */
#define SQLITE_DBCONFIG_ENABLE_FKEY           1002 /* int int* */
#define SQLITE_DBCONFIG_ENABLE_TRIGGER        1003 /* int int* */
#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE      1006 /* int int* */
#define SQLITE_DBCONFIG_ENABLE_QPSG           1007 /* int int* */
#define SQLITE_DBCONFIG_TRIGGER_EQP           1008 /* int int* */
#define SQLITE_DBCONFIG_RESET_DATABASE        1009 /* int int* */
#define SQLITE_DBCONFIG_DEFENSIVE             1010 /* int int* */
#define SQLITE_DBCONFIG_WRITABLE_SCHEMA       1011 /* int int* */
#define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE    1012 /* int int* */
#define SQLITE_DBCONFIG_DQS_DML               1013 /* int int* */
#define SQLITE_DBCONFIG_DQS_DDL               1014 /* int int* */
#define SQLITE_DBCONFIG_ENABLE_VIEW           1015 /* int int* */
#define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT    1016 /* int int* */
#define SQLITE_DBCONFIG_TRUSTED_SCHEMA        1017 /* int int* */
#define SQLITE_DBCONFIG_MAX                   1017 /* Largest DBCONFIG */

/*
** CAPI3REF: Enable Or Disable Extended Result Codes
** METHOD: sqlite3
**
** ^The sqlite3_extended_result_codes() routine enables or disables the
** [extended result codes] feature of SQLite. ^The extended result
** codes are disabled by default for historical compatibility.
*/
    SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);

    /*
    ** CAPI3REF: Last Insert Rowid
    ** METHOD: sqlite3
    **
    ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
    ** has a unique 64-bit signed
    ** integer key called the [ROWID | "rowid"]. ^The rowid is always available
    ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
    ** names are not also used by explicitly declared columns. ^If
    ** the table has a column of type [INTEGER PRIMARY KEY] then that column
    ** is another alias for the rowid.
    **
    ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of
    ** the most recent successful [INSERT] into a rowid table or [virtual table]
    ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not
    ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred
    ** on the database connection D, then sqlite3_last_insert_rowid(D) returns
    ** zero.
    **
    ** As well as being set automatically as rows are inserted into database
    ** tables, the value returned by this function may be set explicitly by
    ** [sqlite3_set_last_insert_rowid()]
    **
    ** Some virtual table implementations may INSERT rows into rowid tables as
    ** part of committing a transaction (e.g. to flush data accumulated in memory
    ** to disk). In this case subsequent calls to this function return the rowid
    ** associated with these internal INSERT operations, which leads to
    ** unintuitive results. Virtual table implementations that do write to rowid
    ** tables in this way can avoid this problem by restoring the original
    ** rowid value using [sqlite3_set_last_insert_rowid()] before returning
    ** control to the user.
    **
    ** ^(If an [INSERT] occurs within a trigger then this routine will
    ** return the [rowid] of the inserted row as long as the trigger is
    ** running. Once the trigger program ends, the value returned
    ** by this routine reverts to what it was before the trigger was fired.)^
    **
    ** ^An [INSERT] that fails due to a constraint violation is not a
    ** successful [INSERT] and does not change the value returned by this
    ** routine.  ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
    ** and INSERT OR ABORT make no changes to the return value of this
    ** routine when their insertion fails.  ^(When INSERT OR REPLACE
    ** encounters a constraint violation, it does not fail.  The
    ** INSERT continues to completion after deleting rows that caused
    ** the constraint problem so INSERT OR REPLACE will always change
    ** the return value of this interface.)^
    **
    ** ^For the purposes of this routine, an [INSERT] is considered to
    ** be successful even if it is subsequently rolled back.
    **
    ** This function is accessible to SQL statements via the
    ** [last_insert_rowid() SQL function].
    **
    ** If a separate thread performs a new [INSERT] on the same
    ** database connection while the [sqlite3_last_insert_rowid()]
    ** function is running and thus changes the last insert [rowid],
    ** then the value returned by [sqlite3_last_insert_rowid()] is
    ** unpredictable and might not equal either the old or the new
    ** last insert [rowid].
    */
    SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);

    /*
    ** CAPI3REF: Set the Last Insert Rowid value.
    ** METHOD: sqlite3
    **
    ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to
    ** set the value returned by calling sqlite3_last_insert_rowid(D) to R
    ** without inserting a row into the database.
    */
    SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*, sqlite3_int64);

    /*
    ** CAPI3REF: Count The Number Of Rows Modified
    ** METHOD: sqlite3
    **
    ** ^This function returns the number of rows modified, inserted or
    ** deleted by the most recently completed INSERT, UPDATE or DELETE
    ** statement on the database connection specified by the only parameter.
    ** ^Executing any other type of SQL statement does not modify the value
    ** returned by this function.
    **
    ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
    ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers],
    ** [foreign key actions] or [REPLACE] constraint resolution are not counted.
    **
    ** Changes to a view that are intercepted by
    ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value
    ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or
    ** DELETE statement run on a view is always zero. Only changes made to real
    ** tables are counted.
    **
    ** Things are more complicated if the sqlite3_changes() function is
    ** executed while a trigger program is running. This may happen if the
    ** program uses the [changes() SQL function], or if some other callback
    ** function invokes sqlite3_changes() directly. Essentially:
    **
    ** <ul>
    **   <li> ^(Before entering a trigger program the value returned by
    **        sqlite3_changes() function is saved. After the trigger program
    **        has finished, the original value is restored.)^
    **
    **   <li> ^(Within a trigger program each INSERT, UPDATE and DELETE
    **        statement sets the value returned by sqlite3_changes()
    **        upon completion as normal. Of course, this value will not include
    **        any changes performed by sub-triggers, as the sqlite3_changes()
    **        value will be saved and restored after each sub-trigger has run.)^
    ** </ul>
    **
    ** ^This means that if the changes() SQL function (or similar) is used
    ** by the first INSERT, UPDATE or DELETE statement within a trigger, it
    ** returns the value as set when the calling statement began executing.
    ** ^If it is used by the second or subsequent such statement within a trigger
    ** program, the value returned reflects the number of rows modified by the
    ** previous INSERT, UPDATE or DELETE statement within the same trigger.
    **
    ** If a separate thread makes changes on the same database connection
    ** while [sqlite3_changes()] is running then the value returned
    ** is unpredictable and not meaningful.
    **
    ** See also:
    ** <ul>
    ** <li> the [sqlite3_total_changes()] interface
    ** <li> the [count_changes pragma]
    ** <li> the [changes() SQL function]
    ** <li> the [data_version pragma]
    ** </ul>
    */
    SQLITE_API int sqlite3_changes(sqlite3*);

    /*
    ** CAPI3REF: Total Number Of Rows Modified
    ** METHOD: sqlite3
    **
    ** ^This function returns the total number of rows inserted, modified or
    ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
    ** since the database connection was opened, including those executed as
    ** part of trigger programs. ^Executing any other type of SQL statement
    ** does not affect the value returned by sqlite3_total_changes().
    **
    ** ^Changes made as part of [foreign key actions] are included in the
    ** count, but those made as part of REPLACE constraint resolution are
    ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers
    ** are not counted.
    **
    ** The [sqlite3_total_changes(D)] interface only reports the number
    ** of rows that changed due to SQL statement run against database
    ** connection D.  Any changes by other database connections are ignored.
    ** To detect changes against a database file from other database
    ** connections use the [PRAGMA data_version] command or the
    ** [SQLITE_FCNTL_DATA_VERSION] [file control].
    **
    ** If a separate thread makes changes on the same database connection
    ** while [sqlite3_total_changes()] is running then the value
    ** returned is unpredictable and not meaningful.
    **
    ** See also:
    ** <ul>
    ** <li> the [sqlite3_changes()] interface
    ** <li> the [count_changes pragma]
    ** <li> the [changes() SQL function]
    ** <li> the [data_version pragma]
    ** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control]
    ** </ul>
    */
    SQLITE_API int sqlite3_total_changes(sqlite3*);

    /*
    ** CAPI3REF: Interrupt A Long-Running Query
    ** METHOD: sqlite3
    **
    ** ^This function causes any pending database operation to abort and
    ** return at its earliest opportunity. This routine is typically
    ** called in response to a user action such as pressing "Cancel"
    ** or Ctrl-C where the user wants a long query operation to halt
    ** immediately.
    **
    ** ^It is safe to call this routine from a thread different from the
    ** thread that is currently running the database operation.  But it
    ** is not safe to call this routine with a [database connection] that
    ** is closed or might close before sqlite3_interrupt() returns.
    **
    ** ^If an SQL operation is very nearly finished at the time when
    ** sqlite3_interrupt() is called, then it might not have an opportunity
    ** to be interrupted and might continue to completion.
    **
    ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
    ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
    ** that is inside an explicit transaction, then the entire transaction
    ** will be rolled back automatically.
    **
    ** ^The sqlite3_interrupt(D) call is in effect until all currently running
    ** SQL statements on [database connection] D complete.  ^Any new SQL statements
    ** that are started after the sqlite3_interrupt() call and before the
    ** running statement count reaches zero are interrupted as if they had been
    ** running prior to the sqlite3_interrupt() call.  ^New SQL statements
    ** that are started after the running statement count reaches zero are
    ** not effected by the sqlite3_interrupt().
    ** ^A call to sqlite3_interrupt(D) that occurs when there are no running
    ** SQL statements is a no-op and has no effect on SQL statements
    ** that are started after the sqlite3_interrupt() call returns.
    */
    SQLITE_API void sqlite3_interrupt(sqlite3*);

    /*
    ** CAPI3REF: Determine If An SQL Statement Is Complete
    **
    ** These routines are useful during command-line input to determine if the
    ** currently entered text seems to form a complete SQL statement or
    ** if additional input is needed before sending the text into
    ** SQLite for parsing.  ^These routines return 1 if the input string
    ** appears to be a complete SQL statement.  ^A statement is judged to be
    ** complete if it ends with a semicolon token and is not a prefix of a
    ** well-formed CREATE TRIGGER statement.  ^Semicolons that are embedded within
    ** string literals or quoted identifier names or comments are not
    ** independent tokens (they are part of the token in which they are
    ** embedded) and thus do not count as a statement terminator.  ^Whitespace
    ** and comments that follow the final semicolon are ignored.
    **
    ** ^These routines return 0 if the statement is incomplete.  ^If a
    ** memory allocation fails, then SQLITE_NOMEM is returned.
    **
    ** ^These routines do not parse the SQL statements thus
    ** will not detect syntactically incorrect SQL.
    **
    ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
    ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
    ** automatically by sqlite3_complete16().  If that initialization fails,
    ** then the return value from sqlite3_complete16() will be non-zero
    ** regardless of whether or not the input SQL is complete.)^
    **
    ** The input to [sqlite3_complete()] must be a zero-terminated
    ** UTF-8 string.
    **
    ** The input to [sqlite3_complete16()] must be a zero-terminated
    ** UTF-16 string in native byte order.
    */
    SQLITE_API int sqlite3_complete(const char* sql);
    SQLITE_API int sqlite3_complete16(const void* sql);

    /*
    ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
    ** KEYWORDS: {busy-handler callback} {busy handler}
    ** METHOD: sqlite3
    **
    ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
    ** that might be invoked with argument P whenever
    ** an attempt is made to access a database table associated with
    ** [database connection] D when another thread
    ** or process has the table locked.
    ** The sqlite3_busy_handler() interface is used to implement
    ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
    **
    ** ^If the busy callback is NULL, then [SQLITE_BUSY]
    ** is returned immediately upon encountering the lock.  ^If the busy callback
    ** is not NULL, then the callback might be invoked with two arguments.
    **
    ** ^The first argument to the busy handler is a copy of the void* pointer which
    ** is the third argument to sqlite3_busy_handler().  ^The second argument to
    ** the busy handler callback is the number of times that the busy handler has
    ** been invoked previously for the same locking event.  ^If the
    ** busy callback returns 0, then no additional attempts are made to
    ** access the database and [SQLITE_BUSY] is returned
    ** to the application.
    ** ^If the callback returns non-zero, then another attempt
    ** is made to access the database and the cycle repeats.
    **
    ** The presence of a busy handler does not guarantee that it will be invoked
    ** when there is lock contention. ^If SQLite determines that invoking the busy
    ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
    ** to the application instead of invoking the
    ** busy handler.
    ** Consider a scenario where one process is holding a read lock that
    ** it is trying to promote to a reserved lock and
    ** a second process is holding a reserved lock that it is trying
    ** to promote to an exclusive lock.  The first process cannot proceed
    ** because it is blocked by the second and the second process cannot
    ** proceed because it is blocked by the first.  If both processes
    ** invoke the busy handlers, neither will make any progress.  Therefore,
    ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
    ** will induce the first process to release its read lock and allow
    ** the second process to proceed.
    **
    ** ^The default busy callback is NULL.
    **
    ** ^(There can only be a single busy handler defined for each
    ** [database connection].  Setting a new busy handler clears any
    ** previously set handler.)^  ^Note that calling [sqlite3_busy_timeout()]
    ** or evaluating [PRAGMA busy_timeout=N] will change the
    ** busy handler and thus clear any previously set busy handler.
    **
    ** The busy callback should not take any actions which modify the
    ** database connection that invoked the busy handler.  In other words,
    ** the busy handler is not reentrant.  Any such actions
    ** result in undefined behavior.
    **
    ** A busy handler must not close the database connection
    ** or [prepared statement] that invoked the busy handler.
    */
    SQLITE_API int sqlite3_busy_handler(sqlite3*, int(*)(void*, int), void*);

    /*
    ** CAPI3REF: Set A Busy Timeout
    ** METHOD: sqlite3
    **
    ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
    ** for a specified amount of time when a table is locked.  ^The handler
    ** will sleep multiple times until at least "ms" milliseconds of sleeping
    ** have accumulated.  ^After at least "ms" milliseconds of sleeping,
    ** the handler returns 0 which causes [sqlite3_step()] to return
    ** [SQLITE_BUSY].
    **
    ** ^Calling this routine with an argument less than or equal to zero
    ** turns off all busy handlers.
    **
    ** ^(There can only be a single busy handler for a particular
    ** [database connection] at any given moment.  If another busy handler
    ** was defined  (using [sqlite3_busy_handler()]) prior to calling
    ** this routine, that other busy handler is cleared.)^
    **
    ** See also:  [PRAGMA busy_timeout]
    */
    SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);

    /*
    ** CAPI3REF: Convenience Routines For Running Queries
    ** METHOD: sqlite3
    **
    ** This is a legacy interface that is preserved for backwards compatibility.
    ** Use of this interface is not recommended.
    **
    ** Definition: A <b>result table</b> is memory data structure created by the
    ** [sqlite3_get_table()] interface.  A result table records the
    ** complete query results from one or more queries.
    **
    ** The table conceptually has a number of rows and columns.  But
    ** these numbers are not part of the result table itself.  These
    ** numbers are obtained separately.  Let N be the number of rows
    ** and M be the number of columns.
    **
    ** A result table is an array of pointers to zero-terminated UTF-8 strings.
    ** There are (N+1)*M elements in the array.  The first M pointers point
    ** to zero-terminated strings that  contain the names of the columns.
    ** The remaining entries all point to query results.  NULL values result
    ** in NULL pointers.  All other values are in their UTF-8 zero-terminated
    ** string representation as returned by [sqlite3_column_text()].
    **
    ** A result table might consist of one or more memory allocations.
    ** It is not safe to pass a result table directly to [sqlite3_free()].
    ** A result table should be deallocated using [sqlite3_free_table()].
    **
    ** ^(As an example of the result table format, suppose a query result
    ** is as follows:
    **
    ** <blockquote><pre>
    **        Name        | Age
    **        -----------------------
    **        Alice       | 43
    **        Bob         | 28
    **        Cindy       | 21
    ** </pre></blockquote>
    **
    ** There are two columns (M==2) and three rows (N==3).  Thus the
    ** result table has 8 entries.  Suppose the result table is stored
    ** in an array named azResult.  Then azResult holds this content:
    **
    ** <blockquote><pre>
    **        azResult&#91;0] = "Name";
    **        azResult&#91;1] = "Age";
    **        azResult&#91;2] = "Alice";
    **        azResult&#91;3] = "43";
    **        azResult&#91;4] = "Bob";
    **        azResult&#91;5] = "28";
    **        azResult&#91;6] = "Cindy";
    **        azResult&#91;7] = "21";
    ** </pre></blockquote>)^
    **
    ** ^The sqlite3_get_table() function evaluates one or more
    ** semicolon-separated SQL statements in the zero-terminated UTF-8
    ** string of its 2nd parameter and returns a result table to the
    ** pointer given in its 3rd parameter.
    **
    ** After the application has finished with the result from sqlite3_get_table(),
    ** it must pass the result table pointer to sqlite3_free_table() in order to
    ** release the memory that was malloced.  Because of the way the
    ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
    ** function must not try to call [sqlite3_free()] directly.  Only
    ** [sqlite3_free_table()] is able to release the memory properly and safely.
    **
    ** The sqlite3_get_table() interface is implemented as a wrapper around
    ** [sqlite3_exec()].  The sqlite3_get_table() routine does not have access
    ** to any internal data structures of SQLite.  It uses only the public
    ** interface defined here.  As a consequence, errors that occur in the
    ** wrapper layer outside of the internal [sqlite3_exec()] call are not
    ** reflected in subsequent calls to [sqlite3_errcode()] or
    ** [sqlite3_errmsg()].
    */
    SQLITE_API int sqlite3_get_table(
        sqlite3* db,          /* An open database */
        const char* zSql,     /* SQL to be evaluated */
        char*** pazResult,    /* Results of the query */
        int* pnRow,           /* Number of result rows written here */
        int* pnColumn,        /* Number of result columns written here */
        char** pzErrmsg       /* Error msg written here */
    );
    SQLITE_API void sqlite3_free_table(char** result);

    /*
    ** CAPI3REF: Formatted String Printing Functions
    **
    ** These routines are work-alikes of the "printf()" family of functions
    ** from the standard C library.
    ** These routines understand most of the common formatting options from
    ** the standard library printf()
    ** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]).
    ** See the [built-in printf()] documentation for details.
    **
    ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
    ** results into memory obtained from [sqlite3_malloc64()].
    ** The strings returned by these two routines should be
    ** released by [sqlite3_free()].  ^Both routines return a
    ** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough
    ** memory to hold the resulting string.
    **
    ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
    ** the standard C library.  The result is written into the
    ** buffer supplied as the second parameter whose size is given by
    ** the first parameter. Note that the order of the
    ** first two parameters is reversed from snprintf().)^  This is an
    ** historical accident that cannot be fixed without breaking
    ** backwards compatibility.  ^(Note also that sqlite3_snprintf()
    ** returns a pointer to its buffer instead of the number of
    ** characters actually written into the buffer.)^  We admit that
    ** the number of characters written would be a more useful return
    ** value but we cannot change the implementation of sqlite3_snprintf()
    ** now without breaking compatibility.
    **
    ** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
    ** guarantees that the buffer is always zero-terminated.  ^The first
    ** parameter "n" is the total size of the buffer, including space for
    ** the zero terminator.  So the longest string that can be completely
    ** written will be n-1 characters.
    **
    ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
    **
    ** See also:  [built-in printf()], [printf() SQL function]
    */
    SQLITE_API char* sqlite3_mprintf(const char*, ...);
    SQLITE_API char* sqlite3_vmprintf(const char*, va_list);
    SQLITE_API char* sqlite3_snprintf(int, char*, const char*, ...);
    SQLITE_API char* sqlite3_vsnprintf(int, char*, const char*, va_list);

    /*
    ** CAPI3REF: Memory Allocation Subsystem
    **
    ** The SQLite core uses these three routines for all of its own
    ** internal memory allocation needs. "Core" in the previous sentence
    ** does not include operating-system specific [VFS] implementation.  The
    ** Windows VFS uses native malloc() and free() for some operations.
    **
    ** ^The sqlite3_malloc() routine returns a pointer to a block
    ** of memory at least N bytes in length, where N is the parameter.
    ** ^If sqlite3_malloc() is unable to obtain sufficient free
    ** memory, it returns a NULL pointer.  ^If the parameter N to
    ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
    ** a NULL pointer.
    **
    ** ^The sqlite3_malloc64(N) routine works just like
    ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
    ** of a signed 32-bit integer.
    **
    ** ^Calling sqlite3_free() with a pointer previously returned
    ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
    ** that it might be reused.  ^The sqlite3_free() routine is
    ** a no-op if is called with a NULL pointer.  Passing a NULL pointer
    ** to sqlite3_free() is harmless.  After being freed, memory
    ** should neither be read nor written.  Even reading previously freed
    ** memory might result in a segmentation fault or other severe error.
    ** Memory corruption, a segmentation fault, or other severe error
    ** might result if sqlite3_free() is called with a non-NULL pointer that
    ** was not obtained from sqlite3_malloc() or sqlite3_realloc().
    **
    ** ^The sqlite3_realloc(X,N) interface attempts to resize a
    ** prior memory allocation X to be at least N bytes.
    ** ^If the X parameter to sqlite3_realloc(X,N)
    ** is a NULL pointer then its behavior is identical to calling
    ** sqlite3_malloc(N).
    ** ^If the N parameter to sqlite3_realloc(X,N) is zero or
    ** negative then the behavior is exactly the same as calling
    ** sqlite3_free(X).
    ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
    ** of at least N bytes in size or NULL if insufficient memory is available.
    ** ^If M is the size of the prior allocation, then min(N,M) bytes
    ** of the prior allocation are copied into the beginning of buffer returned
    ** by sqlite3_realloc(X,N) and the prior allocation is freed.
    ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
    ** prior allocation is not freed.
    **
    ** ^The sqlite3_realloc64(X,N) interfaces works the same as
    ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
    ** of a 32-bit signed integer.
    **
    ** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
    ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
    ** sqlite3_msize(X) returns the size of that memory allocation in bytes.
    ** ^The value returned by sqlite3_msize(X) might be larger than the number
    ** of bytes requested when X was allocated.  ^If X is a NULL pointer then
    ** sqlite3_msize(X) returns zero.  If X points to something that is not
    ** the beginning of memory allocation, or if it points to a formerly
    ** valid memory allocation that has now been freed, then the behavior
    ** of sqlite3_msize(X) is undefined and possibly harmful.
    **
    ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
    ** sqlite3_malloc64(), and sqlite3_realloc64()
    ** is always aligned to at least an 8 byte boundary, or to a
    ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
    ** option is used.
    **
    ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
    ** must be either NULL or else pointers obtained from a prior
    ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
    ** not yet been released.
    **
    ** The application must not read or write any part of
    ** a block of memory after it has been released using
    ** [sqlite3_free()] or [sqlite3_realloc()].
    */
    SQLITE_API void* sqlite3_malloc(int);
    SQLITE_API void* sqlite3_malloc64(sqlite3_uint64);
    SQLITE_API void* sqlite3_realloc(void*, int);
    SQLITE_API void* sqlite3_realloc64(void*, sqlite3_uint64);
    SQLITE_API void sqlite3_free(void*);
    SQLITE_API sqlite3_uint64 sqlite3_msize(void*);

    /*
    ** CAPI3REF: Memory Allocator Statistics
    **
    ** SQLite provides these two interfaces for reporting on the status
    ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
    ** routines, which form the built-in memory allocation subsystem.
    **
    ** ^The [sqlite3_memory_used()] routine returns the number of bytes
    ** of memory currently outstanding (malloced but not freed).
    ** ^The [sqlite3_memory_highwater()] routine returns the maximum
    ** value of [sqlite3_memory_used()] since the high-water mark
    ** was last reset.  ^The values returned by [sqlite3_memory_used()] and
    ** [sqlite3_memory_highwater()] include any overhead
    ** added by SQLite in its implementation of [sqlite3_malloc()],
    ** but not overhead added by the any underlying system library
    ** routines that [sqlite3_malloc()] may call.
    **
    ** ^The memory high-water mark is reset to the current value of
    ** [sqlite3_memory_used()] if and only if the parameter to
    ** [sqlite3_memory_highwater()] is true.  ^The value returned
    ** by [sqlite3_memory_highwater(1)] is the high-water mark
    ** prior to the reset.
    */
    SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
    SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);

    /*
    ** CAPI3REF: Pseudo-Random Number Generator
    **
    ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
    ** select random [ROWID | ROWIDs] when inserting new records into a table that
    ** already uses the largest possible [ROWID].  The PRNG is also used for
    ** the built-in random() and randomblob() SQL functions.  This interface allows
    ** applications to access the same PRNG for other purposes.
    **
    ** ^A call to this routine stores N bytes of randomness into buffer P.
    ** ^The P parameter can be a NULL pointer.
    **
    ** ^If this routine has not been previously called or if the previous
    ** call had N less than one or a NULL pointer for P, then the PRNG is
    ** seeded using randomness obtained from the xRandomness method of
    ** the default [sqlite3_vfs] object.
    ** ^If the previous call to this routine had an N of 1 or more and a
    ** non-NULL P then the pseudo-randomness is generated
    ** internally and without recourse to the [sqlite3_vfs] xRandomness
    ** method.
    */
    SQLITE_API void sqlite3_randomness(int N, void* P);

    /*
    ** CAPI3REF: Compile-Time Authorization Callbacks
    ** METHOD: sqlite3
    ** KEYWORDS: {authorizer callback}
    **
    ** ^This routine registers an authorizer callback with a particular
    ** [database connection], supplied in the first argument.
    ** ^The authorizer callback is invoked as SQL statements are being compiled
    ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
    ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()],
    ** and [sqlite3_prepare16_v3()].  ^At various
    ** points during the compilation process, as logic is being created
    ** to perform various actions, the authorizer callback is invoked to
    ** see if those actions are allowed.  ^The authorizer callback should
    ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
    ** specific action but allow the SQL statement to continue to be
    ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
    ** rejected with an error.  ^If the authorizer callback returns
    ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
    ** then the [sqlite3_prepare_v2()] or equivalent call that triggered
    ** the authorizer will fail with an error message.
    **
    ** When the callback returns [SQLITE_OK], that means the operation
    ** requested is ok.  ^When the callback returns [SQLITE_DENY], the
    ** [sqlite3_prepare_v2()] or equivalent call that triggered the
    ** authorizer will fail with an error message explaining that
    ** access is denied.
    **
    ** ^The first parameter to the authorizer callback is a copy of the third
    ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
    ** to the callback is an integer [SQLITE_COPY | action code] that specifies
    ** the particular action to be authorized. ^The third through sixth parameters
    ** to the callback are either NULL pointers or zero-terminated strings
    ** that contain additional details about the action to be authorized.
    ** Applications must always be prepared to encounter a NULL pointer in any
    ** of the third through the sixth parameters of the authorization callback.
    **
    ** ^If the action code is [SQLITE_READ]
    ** and the callback returns [SQLITE_IGNORE] then the
    ** [prepared statement] statement is constructed to substitute
    ** a NULL value in place of the table column that would have
    ** been read if [SQLITE_OK] had been returned.  The [SQLITE_IGNORE]
    ** return can be used to deny an untrusted user access to individual
    ** columns of a table.
    ** ^When a table is referenced by a [SELECT] but no column values are
    ** extracted from that table (for example in a query like
    ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback
    ** is invoked once for that table with a column name that is an empty string.
    ** ^If the action code is [SQLITE_DELETE] and the callback returns
    ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
    ** [truncate optimization] is disabled and all rows are deleted individually.
    **
    ** An authorizer is used when [sqlite3_prepare | preparing]
    ** SQL statements from an untrusted source, to ensure that the SQL statements
    ** do not try to access data they are not allowed to see, or that they do not
    ** try to execute malicious statements that damage the database.  For
    ** example, an application may allow a user to enter arbitrary
    ** SQL queries for evaluation by a database.  But the application does
    ** not want the user to be able to make arbitrary changes to the
    ** database.  An authorizer could then be put in place while the
    ** user-entered SQL is being [sqlite3_prepare | prepared] that
    ** disallows everything except [SELECT] statements.
    **
    ** Applications that need to process SQL from untrusted sources
    ** might also consider lowering resource limits using [sqlite3_limit()]
    ** and limiting database size using the [max_page_count] [PRAGMA]
    ** in addition to using an authorizer.
    **
    ** ^(Only a single authorizer can be in place on a database connection
    ** at a time.  Each call to sqlite3_set_authorizer overrides the
    ** previous call.)^  ^Disable the authorizer by installing a NULL callback.
    ** The authorizer is disabled by default.
    **
    ** The authorizer callback must not do anything that will modify
    ** the database connection that invoked the authorizer callback.
    ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
    ** database connections for the meaning of "modify" in this paragraph.
    **
    ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
    ** statement might be re-prepared during [sqlite3_step()] due to a
    ** schema change.  Hence, the application should ensure that the
    ** correct authorizer callback remains in place during the [sqlite3_step()].
    **
    ** ^Note that the authorizer callback is invoked only during
    ** [sqlite3_prepare()] or its variants.  Authorization is not
    ** performed during statement evaluation in [sqlite3_step()], unless
    ** as stated in the previous paragraph, sqlite3_step() invokes
    ** sqlite3_prepare_v2() to reprepare a statement after a schema change.
    */
    SQLITE_API int sqlite3_set_authorizer(
        sqlite3*,
        int (*xAuth)(void*, int, const char*, const char*, const char*, const char*),
        void* pUserData
    );

    /*
    ** CAPI3REF: Authorizer Return Codes
    **
    ** The [sqlite3_set_authorizer | authorizer callback function] must
    ** return either [SQLITE_OK] or one of these two constants in order
    ** to signal SQLite whether or not the action is permitted.  See the
    ** [sqlite3_set_authorizer | authorizer documentation] for additional
    ** information.
    **
    ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
    ** returned from the [sqlite3_vtab_on_conflict()] interface.
    */
#define SQLITE_DENY   1   /* Abort the SQL statement with an error */
#define SQLITE_IGNORE 2   /* Don't allow access, but don't generate an error */

    /*
    ** CAPI3REF: Authorizer Action Codes
    **
    ** The [sqlite3_set_authorizer()] interface registers a callback function
    ** that is invoked to authorize certain SQL statement actions.  The
    ** second parameter to the callback is an integer code that specifies
    ** what action is being authorized.  These are the integer action codes that
    ** the authorizer callback may be passed.
    **
    ** These action code values signify what kind of operation is to be
    ** authorized.  The 3rd and 4th parameters to the authorization
    ** callback function will be parameters or NULL depending on which of these
    ** codes is used as the second parameter.  ^(The 5th parameter to the
    ** authorizer callback is the name of the database ("main", "temp",
    ** etc.) if applicable.)^  ^The 6th parameter to the authorizer callback
    ** is the name of the inner-most trigger or view that is responsible for
    ** the access attempt or NULL if this access attempt is directly from
    ** top-level SQL code.
    */
    /******************************************* 3rd ************ 4th ***********/
#define SQLITE_CREATE_INDEX          1   /* Index Name      Table Name      */
#define SQLITE_CREATE_TABLE          2   /* Table Name      NULL            */
#define SQLITE_CREATE_TEMP_INDEX     3   /* Index Name      Table Name      */
#define SQLITE_CREATE_TEMP_TABLE     4   /* Table Name      NULL            */
#define SQLITE_CREATE_TEMP_TRIGGER   5   /* Trigger Name    Table Name      */
#define SQLITE_CREATE_TEMP_VIEW      6   /* View Name       NULL            */
#define SQLITE_CREATE_TRIGGER        7   /* Trigger Name    Table Name      */
#define SQLITE_CREATE_VIEW           8   /* View Name       NULL            */
#define SQLITE_DELETE                9   /* Table Name      NULL            */
#define SQLITE_DROP_INDEX           10   /* Index Name      Table Name      */
#define SQLITE_DROP_TABLE           11   /* Table Name      NULL            */
#define SQLITE_DROP_TEMP_INDEX      12   /* Index Name      Table Name      */
#define SQLITE_DROP_TEMP_TABLE      13   /* Table Name      NULL            */
#define SQLITE_DROP_TEMP_TRIGGER    14   /* Trigger Name    Table Name      */
#define SQLITE_DROP_TEMP_VIEW       15   /* View Name       NULL            */
#define SQLITE_DROP_TRIGGER         16   /* Trigger Name    Table Name      */
#define SQLITE_DROP_VIEW            17   /* View Name       NULL            */
#define SQLITE_INSERT               18   /* Table Name      NULL            */
#define SQLITE_PRAGMA               19   /* Pragma Name     1st arg or NULL */
#define SQLITE_READ                 20   /* Table Name      Column Name     */
#define SQLITE_SELECT               21   /* NULL            NULL            */
#define SQLITE_TRANSACTION          22   /* Operation       NULL            */
#define SQLITE_UPDATE               23   /* Table Name      Column Name     */
#define SQLITE_ATTACH               24   /* Filename        NULL            */
#define SQLITE_DETACH               25   /* Database Name   NULL            */
#define SQLITE_ALTER_TABLE          26   /* Database Name   Table Name      */
#define SQLITE_REINDEX              27   /* Index Name      NULL            */
#define SQLITE_ANALYZE              28   /* Table Name      NULL            */
#define SQLITE_CREATE_VTABLE        29   /* Table Name      Module Name     */
#define SQLITE_DROP_VTABLE          30   /* Table Name      Module Name     */
#define SQLITE_FUNCTION             31   /* NULL            Function Name   */
#define SQLITE_SAVEPOINT            32   /* Operation       Savepoint Name  */
#define SQLITE_COPY                  0   /* No longer used */
#define SQLITE_RECURSIVE            33   /* NULL            NULL            */

/*
** CAPI3REF: Tracing And Profiling Functions
** METHOD: sqlite3
**
** These routines are deprecated. Use the [sqlite3_trace_v2()] interface
** instead of the routines described here.
**
** These routines register callback functions that can be used for
** tracing and profiling the execution of SQL statements.
**
** ^The callback function registered by sqlite3_trace() is invoked at
** various times when an SQL statement is being run by [sqlite3_step()].
** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
** SQL statement text as the statement first begins executing.
** ^(Additional sqlite3_trace() callbacks might occur
** as each triggered subprogram is entered.  The callbacks for triggers
** contain a UTF-8 SQL comment that identifies the trigger.)^
**
** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
** the length of [bound parameter] expansion in the output of sqlite3_trace().
**
** ^The callback function registered by sqlite3_profile() is invoked
** as each SQL statement finishes.  ^The profile callback contains
** the original statement text and an estimate of wall-clock time
** of how long that statement took to run.  ^The profile callback
** time is in units of nanoseconds, however the current implementation
** is only capable of millisecond resolution so the six least significant
** digits in the time are meaningless.  Future versions of SQLite
** might provide greater resolution on the profiler callback.  Invoking
** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the
** profile callback.
*/
    SQLITE_API SQLITE_DEPRECATED void* sqlite3_trace(sqlite3*,
        void(*xTrace)(void*, const char*), void*);
    SQLITE_API SQLITE_DEPRECATED void* sqlite3_profile(sqlite3*,
        void(*xProfile)(void*, const char*, sqlite3_uint64), void*);

    /*
    ** CAPI3REF: SQL Trace Event Codes
    ** KEYWORDS: SQLITE_TRACE
    **
    ** These constants identify classes of events that can be monitored
    ** using the [sqlite3_trace_v2()] tracing logic.  The M argument
    ** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of
    ** the following constants.  ^The first argument to the trace callback
    ** is one of the following constants.
    **
    ** New tracing constants may be added in future releases.
    **
    ** ^A trace callback has four arguments: xCallback(T,C,P,X).
    ** ^The T argument is one of the integer type codes above.
    ** ^The C argument is a copy of the context pointer passed in as the
    ** fourth argument to [sqlite3_trace_v2()].
    ** The P and X arguments are pointers whose meanings depend on T.
    **
    ** <dl>
    ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt>
    ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement
    ** first begins running and possibly at other times during the
    ** execution of the prepared statement, such as at the start of each
    ** trigger subprogram. ^The P argument is a pointer to the
    ** [prepared statement]. ^The X argument is a pointer to a string which
    ** is the unexpanded SQL text of the prepared statement or an SQL comment
    ** that indicates the invocation of a trigger.  ^The callback can compute
    ** the same text that would have been returned by the legacy [sqlite3_trace()]
    ** interface by using the X argument when X begins with "--" and invoking
    ** [sqlite3_expanded_sql(P)] otherwise.
    **
    ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt>
    ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same
    ** information as is provided by the [sqlite3_profile()] callback.
    ** ^The P argument is a pointer to the [prepared statement] and the
    ** X argument points to a 64-bit integer which is the estimated of
    ** the number of nanosecond that the prepared statement took to run.
    ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes.
    **
    ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt>
    ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared
    ** statement generates a single row of result.
    ** ^The P argument is a pointer to the [prepared statement] and the
    ** X argument is unused.
    **
    ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt>
    ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database
    ** connection closes.
    ** ^The P argument is a pointer to the [database connection] object
    ** and the X argument is unused.
    ** </dl>
    */
#define SQLITE_TRACE_STMT       0x01
#define SQLITE_TRACE_PROFILE    0x02
#define SQLITE_TRACE_ROW        0x04
#define SQLITE_TRACE_CLOSE      0x08

    /*
    ** CAPI3REF: SQL Trace Hook
    ** METHOD: sqlite3
    **
    ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback
    ** function X against [database connection] D, using property mask M
    ** and context pointer P.  ^If the X callback is
    ** NULL or if the M mask is zero, then tracing is disabled.  The
    ** M argument should be the bitwise OR-ed combination of
    ** zero or more [SQLITE_TRACE] constants.
    **
    ** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides
    ** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2().
    **
    ** ^The X callback is invoked whenever any of the events identified by
    ** mask M occur.  ^The integer return value from the callback is currently
    ** ignored, though this may change in future releases.  Callback
    ** implementations should return zero to ensure future compatibility.
    **
    ** ^A trace callback is invoked with four arguments: callback(T,C,P,X).
    ** ^The T argument is one of the [SQLITE_TRACE]
    ** constants to indicate why the callback was invoked.
    ** ^The C argument is a copy of the context pointer.
    ** The P and X arguments are pointers whose meanings depend on T.
    **
    ** The sqlite3_trace_v2() interface is intended to replace the legacy
    ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which
    ** are deprecated.
    */
    SQLITE_API int sqlite3_trace_v2(
        sqlite3*,
        unsigned uMask,
        int(*xCallback)(unsigned, void*, void*, void*),
        void* pCtx
    );

    /*
    ** CAPI3REF: Query Progress Callbacks
    ** METHOD: sqlite3
    **
    ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
    ** function X to be invoked periodically during long running calls to
    ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for
    ** database connection D.  An example use for this
    ** interface is to keep a GUI updated during a large query.
    **
    ** ^The parameter P is passed through as the only parameter to the
    ** callback function X.  ^The parameter N is the approximate number of
    ** [virtual machine instructions] that are evaluated between successive
    ** invocations of the callback X.  ^If N is less than one then the progress
    ** handler is disabled.
    **
    ** ^Only a single progress handler may be defined at one time per
    ** [database connection]; setting a new progress handler cancels the
    ** old one.  ^Setting parameter X to NULL disables the progress handler.
    ** ^The progress handler is also disabled by setting N to a value less
    ** than 1.
    **
    ** ^If the progress callback returns non-zero, the operation is
    ** interrupted.  This feature can be used to implement a
    ** "Cancel" button on a GUI progress dialog box.
    **
    ** The progress handler callback must not do anything that will modify
    ** the database connection that invoked the progress handler.
    ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
    ** database connections for the meaning of "modify" in this paragraph.
    **
    */
    SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);

    /*
    ** CAPI3REF: Opening A New Database Connection
    ** CONSTRUCTOR: sqlite3
    **
    ** ^These routines open an SQLite database file as specified by the
    ** filename argument. ^The filename argument is interpreted as UTF-8 for
    ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
    ** order for sqlite3_open16(). ^(A [database connection] handle is usually
    ** returned in *ppDb, even if an error occurs.  The only exception is that
    ** if SQLite is unable to allocate memory to hold the [sqlite3] object,
    ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
    ** object.)^ ^(If the database is opened (and/or created) successfully, then
    ** [SQLITE_OK] is returned.  Otherwise an [error code] is returned.)^ ^The
    ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
    ** an English language description of the error following a failure of any
    ** of the sqlite3_open() routines.
    **
    ** ^The default encoding will be UTF-8 for databases created using
    ** sqlite3_open() or sqlite3_open_v2().  ^The default encoding for databases
    ** created using sqlite3_open16() will be UTF-16 in the native byte order.
    **
    ** Whether or not an error occurs when it is opened, resources
    ** associated with the [database connection] handle should be released by
    ** passing it to [sqlite3_close()] when it is no longer required.
    **
    ** The sqlite3_open_v2() interface works like sqlite3_open()
    ** except that it accepts two additional parameters for additional control
    ** over the new database connection.  ^(The flags parameter to
    ** sqlite3_open_v2() must include, at a minimum, one of the following
    ** three flag combinations:)^
    **
    ** <dl>
    ** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
    ** <dd>The database is opened in read-only mode.  If the database does not
    ** already exist, an error is returned.</dd>)^
    **
    ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
    ** <dd>The database is opened for reading and writing if possible, or reading
    ** only if the file is write protected by the operating system.  In either
    ** case the database must already exist, otherwise an error is returned.</dd>)^
    **
    ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
    ** <dd>The database is opened for reading and writing, and is created if
    ** it does not already exist. This is the behavior that is always used for
    ** sqlite3_open() and sqlite3_open16().</dd>)^
    ** </dl>
    **
    ** In addition to the required flags, the following optional flags are
    ** also supported:
    **
    ** <dl>
    ** ^(<dt>[SQLITE_OPEN_URI]</dt>
    ** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^
    **
    ** ^(<dt>[SQLITE_OPEN_MEMORY]</dt>
    ** <dd>The database will be opened as an in-memory database.  The database
    ** is named by the "filename" argument for the purposes of cache-sharing,
    ** if shared cache mode is enabled, but the "filename" is otherwise ignored.
    ** </dd>)^
    **
    ** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt>
    ** <dd>The new database connection will use the "multi-thread"
    ** [threading mode].)^  This means that separate threads are allowed
    ** to use SQLite at the same time, as long as each thread is using
    ** a different [database connection].
    **
    ** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt>
    ** <dd>The new database connection will use the "serialized"
    ** [threading mode].)^  This means the multiple threads can safely
    ** attempt to use the same database connection at the same time.
    ** (Mutexes will block any actual concurrency, but in this mode
    ** there is no harm in trying.)
    **
    ** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt>
    ** <dd>The database is opened [shared cache] enabled, overriding
    ** the default shared cache setting provided by
    ** [sqlite3_enable_shared_cache()].)^
    **
    ** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt>
    ** <dd>The database is opened [shared cache] disabled, overriding
    ** the default shared cache setting provided by
    ** [sqlite3_enable_shared_cache()].)^
    **
    ** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt>
    ** <dd>The database filename is not allowed to be a symbolic link</dd>
    ** </dl>)^
    **
    ** If the 3rd parameter to sqlite3_open_v2() is not one of the
    ** required combinations shown above optionally combined with other
    ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
    ** then the behavior is undefined.
    **
    ** ^The fourth parameter to sqlite3_open_v2() is the name of the
    ** [sqlite3_vfs] object that defines the operating system interface that
    ** the new database connection should use.  ^If the fourth parameter is
    ** a NULL pointer then the default [sqlite3_vfs] object is used.
    **
    ** ^If the filename is ":memory:", then a private, temporary in-memory database
    ** is created for the connection.  ^This in-memory database will vanish when
    ** the database connection is closed.  Future versions of SQLite might
    ** make use of additional special filenames that begin with the ":" character.
    ** It is recommended that when a database filename actually does begin with
    ** a ":" character you should prefix the filename with a pathname such as
    ** "./" to avoid ambiguity.
    **
    ** ^If the filename is an empty string, then a private, temporary
    ** on-disk database will be created.  ^This private database will be
    ** automatically deleted as soon as the database connection is closed.
    **
    ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
    **
    ** ^If [URI filename] interpretation is enabled, and the filename argument
    ** begins with "file:", then the filename is interpreted as a URI. ^URI
    ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
    ** set in the third argument to sqlite3_open_v2(), or if it has
    ** been enabled globally using the [SQLITE_CONFIG_URI] option with the
    ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
    ** URI filename interpretation is turned off
    ** by default, but future releases of SQLite might enable URI filename
    ** interpretation by default.  See "[URI filenames]" for additional
    ** information.
    **
    ** URI filenames are parsed according to RFC 3986. ^If the URI contains an
    ** authority, then it must be either an empty string or the string
    ** "localhost". ^If the authority is not an empty string or "localhost", an
    ** error is returned to the caller. ^The fragment component of a URI, if
    ** present, is ignored.
    **
    ** ^SQLite uses the path component of the URI as the name of the disk file
    ** which contains the database. ^If the path begins with a '/' character,
    ** then it is interpreted as an absolute path. ^If the path does not begin
    ** with a '/' (meaning that the authority section is omitted from the URI)
    ** then the path is interpreted as a relative path.
    ** ^(On windows, the first component of an absolute path
    ** is a drive specification (e.g. "C:").)^
    **
    ** [[core URI query parameters]]
    ** The query component of a URI may contain parameters that are interpreted
    ** either by SQLite itself, or by a [VFS | custom VFS implementation].
    ** SQLite and its built-in [VFSes] interpret the
    ** following query parameters:
    **
    ** <ul>
    **   <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
    **     a VFS object that provides the operating system interface that should
    **     be used to access the database file on disk. ^If this option is set to
    **     an empty string the default VFS object is used. ^Specifying an unknown
    **     VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
    **     present, then the VFS specified by the option takes precedence over
    **     the value passed as the fourth parameter to sqlite3_open_v2().
    **
    **   <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
    **     "rwc", or "memory". Attempting to set it to any other value is
    **     an error)^.
    **     ^If "ro" is specified, then the database is opened for read-only
    **     access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
    **     third argument to sqlite3_open_v2(). ^If the mode option is set to
    **     "rw", then the database is opened for read-write (but not create)
    **     access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
    **     been set. ^Value "rwc" is equivalent to setting both
    **     SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE.  ^If the mode option is
    **     set to "memory" then a pure [in-memory database] that never reads
    **     or writes from disk is used. ^It is an error to specify a value for
    **     the mode parameter that is less restrictive than that specified by
    **     the flags passed in the third parameter to sqlite3_open_v2().
    **
    **   <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
    **     "private". ^Setting it to "shared" is equivalent to setting the
    **     SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
    **     sqlite3_open_v2(). ^Setting the cache parameter to "private" is
    **     equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
    **     ^If sqlite3_open_v2() is used and the "cache" parameter is present in
    **     a URI filename, its value overrides any behavior requested by setting
    **     SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
    **
    **  <li> <b>psow</b>: ^The psow parameter indicates whether or not the
    **     [powersafe overwrite] property does or does not apply to the
    **     storage media on which the database file resides.
    **
    **  <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
    **     which if set disables file locking in rollback journal modes.  This
    **     is useful for accessing a database on a filesystem that does not
    **     support locking.  Caution:  Database corruption might result if two
    **     or more processes write to the same database and any one of those
    **     processes uses nolock=1.
    **
    **  <li> <b>immutable</b>: ^The immutable parameter is a boolean query
    **     parameter that indicates that the database file is stored on
    **     read-only media.  ^When immutable is set, SQLite assumes that the
    **     database file cannot be changed, even by a process with higher
    **     privilege, and so the database is opened read-only and all locking
    **     and change detection is disabled.  Caution: Setting the immutable
    **     property on a database file that does in fact change can result
    **     in incorrect query results and/or [SQLITE_CORRUPT] errors.
    **     See also: [SQLITE_IOCAP_IMMUTABLE].
    **
    ** </ul>
    **
    ** ^Specifying an unknown parameter in the query component of a URI is not an
    ** error.  Future versions of SQLite might understand additional query
    ** parameters.  See "[query parameters with special meaning to SQLite]" for
    ** additional information.
    **
    ** [[URI filename examples]] <h3>URI filename examples</h3>
    **
    ** <table border="1" align=center cellpadding=5>
    ** <tr><th> URI filenames <th> Results
    ** <tr><td> file:data.db <td>
    **          Open the file "data.db" in the current directory.
    ** <tr><td> file:/home/fred/data.db<br>
    **          file:///home/fred/data.db <br>
    **          file://localhost/home/fred/data.db <br> <td>
    **          Open the database file "/home/fred/data.db".
    ** <tr><td> file://darkstar/home/fred/data.db <td>
    **          An error. "darkstar" is not a recognized authority.
    ** <tr><td style="white-space:nowrap">
    **          file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
    **     <td> Windows only: Open the file "data.db" on fred's desktop on drive
    **          C:. Note that the %20 escaping in this example is not strictly
    **          necessary - space characters can be used literally
    **          in URI filenames.
    ** <tr><td> file:data.db?mode=ro&cache=private <td>
    **          Open file "data.db" in the current directory for read-only access.
    **          Regardless of whether or not shared-cache mode is enabled by
    **          default, use a private cache.
    ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
    **          Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
    **          that uses dot-files in place of posix advisory locking.
    ** <tr><td> file:data.db?mode=readonly <td>
    **          An error. "readonly" is not a valid option for the "mode" parameter.
    **          Use "ro" instead:  "file:data.db?mode=ro".
    ** </table>
    **
    ** ^URI hexadecimal escape sequences (%HH) are supported within the path and
    ** query components of a URI. A hexadecimal escape sequence consists of a
    ** percent sign - "%" - followed by exactly two hexadecimal digits
    ** specifying an octet value. ^Before the path or query components of a
    ** URI filename are interpreted, they are encoded using UTF-8 and all
    ** hexadecimal escape sequences replaced by a single byte containing the
    ** corresponding octet. If this process generates an invalid UTF-8 encoding,
    ** the results are undefined.
    **
    ** <b>Note to Windows users:</b>  The encoding used for the filename argument
    ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
    ** codepage is currently defined.  Filenames containing international
    ** characters must be converted to UTF-8 prior to passing them into
    ** sqlite3_open() or sqlite3_open_v2().
    **
    ** <b>Note to Windows Runtime users:</b>  The temporary directory must be set
    ** prior to calling sqlite3_open() or sqlite3_open_v2().  Otherwise, various
    ** features that require the use of temporary files may fail.
    **
    ** See also: [sqlite3_temp_directory]
    */
    SQLITE_API int sqlite3_open(
        const char* filename,   /* Database filename (UTF-8) */
        sqlite3** ppDb          /* OUT: SQLite db handle */
    );
    SQLITE_API int sqlite3_open16(
        const void* filename,   /* Database filename (UTF-16) */
        sqlite3** ppDb          /* OUT: SQLite db handle */
    );
    SQLITE_API int sqlite3_open_v2(
        const char* filename,   /* Database filename (UTF-8) */
        sqlite3** ppDb,         /* OUT: SQLite db handle */
        int flags,              /* Flags */
        const char* zVfs        /* Name of VFS module to use */
    );

    /*
    ** CAPI3REF: Obtain Values For URI Parameters
    **
    ** These are utility routines, useful to [VFS|custom VFS implementations],
    ** that check if a database file was a URI that contained a specific query
    ** parameter, and if so obtains the value of that query parameter.
    **
    ** The first parameter to these interfaces (hereafter referred to
    ** as F) must be one of:
    ** <ul>
    ** <li> A database filename pointer created by the SQLite core and
    ** passed into the xOpen() method of a VFS implemention, or
    ** <li> A filename obtained from [sqlite3_db_filename()], or
    ** <li> A new filename constructed using [sqlite3_create_filename()].
    ** </ul>
    ** If the F parameter is not one of the above, then the behavior is
    ** undefined and probably undesirable.  Older versions of SQLite were
    ** more tolerant of invalid F parameters than newer versions.
    **
    ** If F is a suitable filename (as described in the previous paragraph)
    ** and if P is the name of the query parameter, then
    ** sqlite3_uri_parameter(F,P) returns the value of the P
    ** parameter if it exists or a NULL pointer if P does not appear as a
    ** query parameter on F.  If P is a query parameter of F and it
    ** has no explicit value, then sqlite3_uri_parameter(F,P) returns
    ** a pointer to an empty string.
    **
    ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
    ** parameter and returns true (1) or false (0) according to the value
    ** of P.  The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
    ** value of query parameter P is one of "yes", "true", or "on" in any
    ** case or if the value begins with a non-zero number.  The
    ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
    ** query parameter P is one of "no", "false", or "off" in any case or
    ** if the value begins with a numeric zero.  If P is not a query
    ** parameter on F or if the value of P does not match any of the
    ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
    **
    ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
    ** 64-bit signed integer and returns that integer, or D if P does not
    ** exist.  If the value of P is something other than an integer, then
    ** zero is returned.
    **
    ** The sqlite3_uri_key(F,N) returns a pointer to the name (not
    ** the value) of the N-th query parameter for filename F, or a NULL
    ** pointer if N is less than zero or greater than the number of query
    ** parameters minus 1.  The N value is zero-based so N should be 0 to obtain
    ** the name of the first query parameter, 1 for the second parameter, and
    ** so forth.
    **
    ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
    ** sqlite3_uri_boolean(F,P,B) returns B.  If F is not a NULL pointer and
    ** is not a database file pathname pointer that the SQLite core passed
    ** into the xOpen VFS method, then the behavior of this routine is undefined
    ** and probably undesirable.
    **
    ** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F
    ** parameter can also be the name of a rollback journal file or WAL file
    ** in addition to the main database file.  Prior to version 3.31.0, these
    ** routines would only work if F was the name of the main database file.
    ** When the F parameter is the name of the rollback journal or WAL file,
    ** it has access to all the same query parameters as were found on the
    ** main database file.
    **
    ** See the [URI filename] documentation for additional information.
    */
    SQLITE_API const char* sqlite3_uri_parameter(const char* zFilename, const char* zParam);
    SQLITE_API int sqlite3_uri_boolean(const char* zFile, const char* zParam, int bDefault);
    SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64);
    SQLITE_API const char* sqlite3_uri_key(const char* zFilename, int N);

    /*
    ** CAPI3REF:  Translate filenames
    **
    ** These routines are available to [VFS|custom VFS implementations] for
    ** translating filenames between the main database file, the journal file,
    ** and the WAL file.
    **
    ** If F is the name of an sqlite database file, journal file, or WAL file
    ** passed by the SQLite core into the VFS, then sqlite3_filename_database(F)
    ** returns the name of the corresponding database file.
    **
    ** If F is the name of an sqlite database file, journal file, or WAL file
    ** passed by the SQLite core into the VFS, or if F is a database filename
    ** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F)
    ** returns the name of the corresponding rollback journal file.
    **
    ** If F is the name of an sqlite database file, journal file, or WAL file
    ** that was passed by the SQLite core into the VFS, or if F is a database
    ** filename obtained from [sqlite3_db_filename()], then
    ** sqlite3_filename_wal(F) returns the name of the corresponding
    ** WAL file.
    **
    ** In all of the above, if F is not the name of a database, journal or WAL
    ** filename passed into the VFS from the SQLite core and F is not the
    ** return value from [sqlite3_db_filename()], then the result is
    ** undefined and is likely a memory access violation.
    */
    SQLITE_API const char* sqlite3_filename_database(const char*);
    SQLITE_API const char* sqlite3_filename_journal(const char*);
    SQLITE_API const char* sqlite3_filename_wal(const char*);

    /*
    ** CAPI3REF:  Database File Corresponding To A Journal
    **
    ** ^If X is the name of a rollback or WAL-mode journal file that is
    ** passed into the xOpen method of [sqlite3_vfs], then
    ** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file]
    ** object that represents the main database file.
    **
    ** This routine is intended for use in custom [VFS] implementations
    ** only.  It is not a general-purpose interface.
    ** The argument sqlite3_file_object(X) must be a filename pointer that
    ** has been passed into [sqlite3_vfs].xOpen method where the
    ** flags parameter to xOpen contains one of the bits
    ** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL].  Any other use
    ** of this routine results in undefined and probably undesirable
    ** behavior.
    */
    SQLITE_API sqlite3_file* sqlite3_database_file_object(const char*);

    /*
    ** CAPI3REF: Create and Destroy VFS Filenames
    **
    ** These interfces are provided for use by [VFS shim] implementations and
    ** are not useful outside of that context.
    **
    ** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of
    ** database filename D with corresponding journal file J and WAL file W and
    ** with N URI parameters key/values pairs in the array P.  The result from
    ** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that
    ** is safe to pass to routines like:
    ** <ul>
    ** <li> [sqlite3_uri_parameter()],
    ** <li> [sqlite3_uri_boolean()],
    ** <li> [sqlite3_uri_int64()],
    ** <li> [sqlite3_uri_key()],
    ** <li> [sqlite3_filename_database()],
    ** <li> [sqlite3_filename_journal()], or
    ** <li> [sqlite3_filename_wal()].
    ** </ul>
    ** If a memory allocation error occurs, sqlite3_create_filename() might
    ** return a NULL pointer.  The memory obtained from sqlite3_create_filename(X)
    ** must be released by a corresponding call to sqlite3_free_filename(Y).
    **
    ** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array
    ** of 2*N pointers to strings.  Each pair of pointers in this array corresponds
    ** to a key and value for a query parameter.  The P parameter may be a NULL
    ** pointer if N is zero.  None of the 2*N pointers in the P array may be
    ** NULL pointers and key pointers should not be empty strings.
    ** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may
    ** be NULL pointers, though they can be empty strings.
    **
    ** The sqlite3_free_filename(Y) routine releases a memory allocation
    ** previously obtained from sqlite3_create_filename().  Invoking
    ** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op.
    **
    ** If the Y parameter to sqlite3_free_filename(Y) is anything other
    ** than a NULL pointer or a pointer previously acquired from
    ** sqlite3_create_filename(), then bad things such as heap
    ** corruption or segfaults may occur. The value Y should not be
    ** used again after sqlite3_free_filename(Y) has been called.  This means
    ** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y,
    ** then the corresponding [sqlite3_module.xClose() method should also be
    ** invoked prior to calling sqlite3_free_filename(Y).
    */
    SQLITE_API char* sqlite3_create_filename(
        const char* zDatabase,
        const char* zJournal,
        const char* zWal,
        int nParam,
        const char** azParam
    );
    SQLITE_API void sqlite3_free_filename(char*);

    /*
    ** CAPI3REF: Error Codes And Messages
    ** METHOD: sqlite3
    **
    ** ^If the most recent sqlite3_* API call associated with
    ** [database connection] D failed, then the sqlite3_errcode(D) interface
    ** returns the numeric [result code] or [extended result code] for that
    ** API call.
    ** ^The sqlite3_extended_errcode()
    ** interface is the same except that it always returns the
    ** [extended result code] even when extended result codes are
    ** disabled.
    **
    ** The values returned by sqlite3_errcode() and/or
    ** sqlite3_extended_errcode() might change with each API call.
    ** Except, there are some interfaces that are guaranteed to never
    ** change the value of the error code.  The error-code preserving
    ** interfaces are:
    **
    ** <ul>
    ** <li> sqlite3_errcode()
    ** <li> sqlite3_extended_errcode()
    ** <li> sqlite3_errmsg()
    ** <li> sqlite3_errmsg16()
    ** </ul>
    **
    ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
    ** text that describes the error, as either UTF-8 or UTF-16 respectively.
    ** ^(Memory to hold the error message string is managed internally.
    ** The application does not need to worry about freeing the result.
    ** However, the error string might be overwritten or deallocated by
    ** subsequent calls to other SQLite interface functions.)^
    **
    ** ^The sqlite3_errstr() interface returns the English-language text
    ** that describes the [result code], as UTF-8.
    ** ^(Memory to hold the error message string is managed internally
    ** and must not be freed by the application)^.
    **
    ** When the serialized [threading mode] is in use, it might be the
    ** case that a second error occurs on a separate thread in between
    ** the time of the first error and the call to these interfaces.
    ** When that happens, the second error will be reported since these
    ** interfaces always report the most recent result.  To avoid
    ** this, each thread can obtain exclusive use of the [database connection] D
    ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
    ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
    ** all calls to the interfaces listed here are completed.
    **
    ** If an interface fails with SQLITE_MISUSE, that means the interface
    ** was invoked incorrectly by the application.  In that case, the
    ** error code and message may or may not be set.
    */
    SQLITE_API int sqlite3_errcode(sqlite3* db);
    SQLITE_API int sqlite3_extended_errcode(sqlite3* db);
    SQLITE_API const char* sqlite3_errmsg(sqlite3*);
    SQLITE_API const void* sqlite3_errmsg16(sqlite3*);
    SQLITE_API const char* sqlite3_errstr(int);

    /*
    ** CAPI3REF: Prepared Statement Object
    ** KEYWORDS: {prepared statement} {prepared statements}
    **
    ** An instance of this object represents a single SQL statement that
    ** has been compiled into binary form and is ready to be evaluated.
    **
    ** Think of each SQL statement as a separate computer program.  The
    ** original SQL text is source code.  A prepared statement object
    ** is the compiled object code.  All SQL must be converted into a
    ** prepared statement before it can be run.
    **
    ** The life-cycle of a prepared statement object usually goes like this:
    **
    ** <ol>
    ** <li> Create the prepared statement object using [sqlite3_prepare_v2()].
    ** <li> Bind values to [parameters] using the sqlite3_bind_*()
    **      interfaces.
    ** <li> Run the SQL by calling [sqlite3_step()] one or more times.
    ** <li> Reset the prepared statement using [sqlite3_reset()] then go back
    **      to step 2.  Do this zero or more times.
    ** <li> Destroy the object using [sqlite3_finalize()].
    ** </ol>
    */
    typedef struct sqlite3_stmt sqlite3_stmt;

    /*
    ** CAPI3REF: Run-time Limits
    ** METHOD: sqlite3
    **
    ** ^(This interface allows the size of various constructs to be limited
    ** on a connection by connection basis.  The first parameter is the
    ** [database connection] whose limit is to be set or queried.  The
    ** second parameter is one of the [limit categories] that define a
    ** class of constructs to be size limited.  The third parameter is the
    ** new limit for that construct.)^
    **
    ** ^If the new limit is a negative number, the limit is unchanged.
    ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
    ** [limits | hard upper bound]
    ** set at compile-time by a C preprocessor macro called
    ** [limits | SQLITE_MAX_<i>NAME</i>].
    ** (The "_LIMIT_" in the name is changed to "_MAX_".))^
    ** ^Attempts to increase a limit above its hard upper bound are
    ** silently truncated to the hard upper bound.
    **
    ** ^Regardless of whether or not the limit was changed, the
    ** [sqlite3_limit()] interface returns the prior value of the limit.
    ** ^Hence, to find the current value of a limit without changing it,
    ** simply invoke this interface with the third parameter set to -1.
    **
    ** Run-time limits are intended for use in applications that manage
    ** both their own internal database and also databases that are controlled
    ** by untrusted external sources.  An example application might be a
    ** web browser that has its own databases for storing history and
    ** separate databases controlled by JavaScript applications downloaded
    ** off the Internet.  The internal databases can be given the
    ** large, default limits.  Databases managed by external sources can
    ** be given much smaller limits designed to prevent a denial of service
    ** attack.  Developers might also want to use the [sqlite3_set_authorizer()]
    ** interface to further control untrusted SQL.  The size of the database
    ** created by an untrusted script can be contained using the
    ** [max_page_count] [PRAGMA].
    **
    ** New run-time limit categories may be added in future releases.
    */
    SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);

    /*
    ** CAPI3REF: Run-Time Limit Categories
    ** KEYWORDS: {limit category} {*limit categories}
    **
    ** These constants define various performance limits
    ** that can be lowered at run-time using [sqlite3_limit()].
    ** The synopsis of the meanings of the various limits is shown below.
    ** Additional information is available at [limits | Limits in SQLite].
    **
    ** <dl>
    ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
    ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
    **
    ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
    ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
    **
    ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
    ** <dd>The maximum number of columns in a table definition or in the
    ** result set of a [SELECT] or the maximum number of columns in an index
    ** or in an ORDER BY or GROUP BY clause.</dd>)^
    **
    ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
    ** <dd>The maximum depth of the parse tree on any expression.</dd>)^
    **
    ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
    ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
    **
    ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
    ** <dd>The maximum number of instructions in a virtual machine program
    ** used to implement an SQL statement.  If [sqlite3_prepare_v2()] or
    ** the equivalent tries to allocate space for more than this many opcodes
    ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^
    **
    ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
    ** <dd>The maximum number of arguments on a function.</dd>)^
    **
    ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
    ** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
    **
    ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
    ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
    ** <dd>The maximum length of the pattern argument to the [LIKE] or
    ** [GLOB] operators.</dd>)^
    **
    ** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
    ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
    ** <dd>The maximum index number of any [parameter] in an SQL statement.)^
    **
    ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
    ** <dd>The maximum depth of recursion for triggers.</dd>)^
    **
    ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt>
    ** <dd>The maximum number of auxiliary worker threads that a single
    ** [prepared statement] may start.</dd>)^
    ** </dl>
    */
#define SQLITE_LIMIT_LENGTH                    0
#define SQLITE_LIMIT_SQL_LENGTH                1
#define SQLITE_LIMIT_COLUMN                    2
#define SQLITE_LIMIT_EXPR_DEPTH                3
#define SQLITE_LIMIT_COMPOUND_SELECT           4
#define SQLITE_LIMIT_VDBE_OP                   5
#define SQLITE_LIMIT_FUNCTION_ARG              6
#define SQLITE_LIMIT_ATTACHED                  7
#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH       8
#define SQLITE_LIMIT_VARIABLE_NUMBER           9
#define SQLITE_LIMIT_TRIGGER_DEPTH            10
#define SQLITE_LIMIT_WORKER_THREADS           11

    /*
    ** CAPI3REF: Prepare Flags
    **
    ** These constants define various flags that can be passed into
    ** "prepFlags" parameter of the [sqlite3_prepare_v3()] and
    ** [sqlite3_prepare16_v3()] interfaces.
    **
    ** New flags may be added in future releases of SQLite.
    **
    ** <dl>
    ** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt>
    ** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner
    ** that the prepared statement will be retained for a long time and
    ** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()]
    ** and [sqlite3_prepare16_v3()] assume that the prepared statement will
    ** be used just once or at most a few times and then destroyed using
    ** [sqlite3_finalize()] relatively soon. The current implementation acts
    ** on this hint by avoiding the use of [lookaside memory] so as not to
    ** deplete the limited store of lookaside memory. Future versions of
    ** SQLite may act on this hint differently.
    **
    ** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt>
    ** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used
    ** to be required for any prepared statement that wanted to use the
    ** [sqlite3_normalized_sql()] interface.  However, the
    ** [sqlite3_normalized_sql()] interface is now available to all
    ** prepared statements, regardless of whether or not they use this
    ** flag.
    **
    ** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt>
    ** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler
    ** to return an error (error code SQLITE_ERROR) if the statement uses
    ** any virtual tables.
    ** </dl>
    */
#define SQLITE_PREPARE_PERSISTENT              0x01
#define SQLITE_PREPARE_NORMALIZE               0x02
#define SQLITE_PREPARE_NO_VTAB                 0x04

    /*
    ** CAPI3REF: Compiling An SQL Statement
    ** KEYWORDS: {SQL statement compiler}
    ** METHOD: sqlite3
    ** CONSTRUCTOR: sqlite3_stmt
    **
    ** To execute an SQL statement, it must first be compiled into a byte-code
    ** program using one of these routines.  Or, in other words, these routines
    ** are constructors for the [prepared statement] object.
    **
    ** The preferred routine to use is [sqlite3_prepare_v2()].  The
    ** [sqlite3_prepare()] interface is legacy and should be avoided.
    ** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used
    ** for special purposes.
    **
    ** The use of the UTF-8 interfaces is preferred, as SQLite currently
    ** does all parsing using UTF-8.  The UTF-16 interfaces are provided
    ** as a convenience.  The UTF-16 interfaces work by converting the
    ** input text into UTF-8, then invoking the corresponding UTF-8 interface.
    **
    ** The first argument, "db", is a [database connection] obtained from a
    ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
    ** [sqlite3_open16()].  The database connection must not have been closed.
    **
    ** The second argument, "zSql", is the statement to be compiled, encoded
    ** as either UTF-8 or UTF-16.  The sqlite3_prepare(), sqlite3_prepare_v2(),
    ** and sqlite3_prepare_v3()
    ** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(),
    ** and sqlite3_prepare16_v3() use UTF-16.
    **
    ** ^If the nByte argument is negative, then zSql is read up to the
    ** first zero terminator. ^If nByte is positive, then it is the
    ** number of bytes read from zSql.  ^If nByte is zero, then no prepared
    ** statement is generated.
    ** If the caller knows that the supplied string is nul-terminated, then
    ** there is a small performance advantage to passing an nByte parameter that
    ** is the number of bytes in the input string <i>including</i>
    ** the nul-terminator.
    **
    ** ^If pzTail is not NULL then *pzTail is made to point to the first byte
    ** past the end of the first SQL statement in zSql.  These routines only
    ** compile the first statement in zSql, so *pzTail is left pointing to
    ** what remains uncompiled.
    **
    ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
    ** executed using [sqlite3_step()].  ^If there is an error, *ppStmt is set
    ** to NULL.  ^If the input text contains no SQL (if the input is an empty
    ** string or a comment) then *ppStmt is set to NULL.
    ** The calling procedure is responsible for deleting the compiled
    ** SQL statement using [sqlite3_finalize()] after it has finished with it.
    ** ppStmt may not be NULL.
    **
    ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
    ** otherwise an [error code] is returned.
    **
    ** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(),
    ** and sqlite3_prepare16_v3() interfaces are recommended for all new programs.
    ** The older interfaces (sqlite3_prepare() and sqlite3_prepare16())
    ** are retained for backwards compatibility, but their use is discouraged.
    ** ^In the "vX" interfaces, the prepared statement
    ** that is returned (the [sqlite3_stmt] object) contains a copy of the
    ** original SQL text. This causes the [sqlite3_step()] interface to
    ** behave differently in three ways:
    **
    ** <ol>
    ** <li>
    ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
    ** always used to do, [sqlite3_step()] will automatically recompile the SQL
    ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
    ** retries will occur before sqlite3_step() gives up and returns an error.
    ** </li>
    **
    ** <li>
    ** ^When an error occurs, [sqlite3_step()] will return one of the detailed
    ** [error codes] or [extended error codes].  ^The legacy behavior was that
    ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
    ** and the application would have to make a second call to [sqlite3_reset()]
    ** in order to find the underlying cause of the problem. With the "v2" prepare
    ** interfaces, the underlying reason for the error is returned immediately.
    ** </li>
    **
    ** <li>
    ** ^If the specific value bound to a [parameter | host parameter] in the
    ** WHERE clause might influence the choice of query plan for a statement,
    ** then the statement will be automatically recompiled, as if there had been
    ** a schema change, on the first [sqlite3_step()] call following any change
    ** to the [sqlite3_bind_text | bindings] of that [parameter].
    ** ^The specific value of a WHERE-clause [parameter] might influence the
    ** choice of query plan if the parameter is the left-hand side of a [LIKE]
    ** or [GLOB] operator or if the parameter is compared to an indexed column
    ** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled.
    ** </li>
    ** </ol>
    **
    ** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having
    ** the extra prepFlags parameter, which is a bit array consisting of zero or
    ** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags.  ^The
    ** sqlite3_prepare_v2() interface works exactly the same as
    ** sqlite3_prepare_v3() with a zero prepFlags parameter.
    */
    SQLITE_API int sqlite3_prepare(
        sqlite3* db,            /* Database handle */
        const char* zSql,       /* SQL statement, UTF-8 encoded */
        int nByte,              /* Maximum length of zSql in bytes. */
        sqlite3_stmt** ppStmt,  /* OUT: Statement handle */
        const char** pzTail     /* OUT: Pointer to unused portion of zSql */
    );
    SQLITE_API int sqlite3_prepare_v2(
        sqlite3* db,            /* Database handle */
        const char* zSql,       /* SQL statement, UTF-8 encoded */
        int nByte,              /* Maximum length of zSql in bytes. */
        sqlite3_stmt** ppStmt,  /* OUT: Statement handle */
        const char** pzTail     /* OUT: Pointer to unused portion of zSql */
    );
    SQLITE_API int sqlite3_prepare_v3(
        sqlite3* db,            /* Database handle */
        const char* zSql,       /* SQL statement, UTF-8 encoded */
        int nByte,              /* Maximum length of zSql in bytes. */
        unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
        sqlite3_stmt** ppStmt,  /* OUT: Statement handle */
        const char** pzTail     /* OUT: Pointer to unused portion of zSql */
    );
    SQLITE_API int sqlite3_prepare16(
        sqlite3* db,            /* Database handle */
        const void* zSql,       /* SQL statement, UTF-16 encoded */
        int nByte,              /* Maximum length of zSql in bytes. */
        sqlite3_stmt** ppStmt,  /* OUT: Statement handle */
        const void** pzTail     /* OUT: Pointer to unused portion of zSql */
    );
    SQLITE_API int sqlite3_prepare16_v2(
        sqlite3* db,            /* Database handle */
        const void* zSql,       /* SQL statement, UTF-16 encoded */
        int nByte,              /* Maximum length of zSql in bytes. */
        sqlite3_stmt** ppStmt,  /* OUT: Statement handle */
        const void** pzTail     /* OUT: Pointer to unused portion of zSql */
    );
    SQLITE_API int sqlite3_prepare16_v3(
        sqlite3* db,            /* Database handle */
        const void* zSql,       /* SQL statement, UTF-16 encoded */
        int nByte,              /* Maximum length of zSql in bytes. */
        unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
        sqlite3_stmt** ppStmt,  /* OUT: Statement handle */
        const void** pzTail     /* OUT: Pointer to unused portion of zSql */
    );

    /*
    ** CAPI3REF: Retrieving Statement SQL
    ** METHOD: sqlite3_stmt
    **
    ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8
    ** SQL text used to create [prepared statement] P if P was
    ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()],
    ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
    ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8
    ** string containing the SQL text of prepared statement P with
    ** [bound parameters] expanded.
    ** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8
    ** string containing the normalized SQL text of prepared statement P.  The
    ** semantics used to normalize a SQL statement are unspecified and subject
    ** to change.  At a minimum, literal values will be replaced with suitable
    ** placeholders.
    **
    ** ^(For example, if a prepared statement is created using the SQL
    ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345
    ** and parameter :xyz is unbound, then sqlite3_sql() will return
    ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()
    ** will return "SELECT 2345,NULL".)^
    **
    ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory
    ** is available to hold the result, or if the result would exceed the
    ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH].
    **
    ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of
    ** bound parameter expansions.  ^The [SQLITE_OMIT_TRACE] compile-time
    ** option causes sqlite3_expanded_sql() to always return NULL.
    **
    ** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P)
    ** are managed by SQLite and are automatically freed when the prepared
    ** statement is finalized.
    ** ^The string returned by sqlite3_expanded_sql(P), on the other hand,
    ** is obtained from [sqlite3_malloc()] and must be free by the application
    ** by passing it to [sqlite3_free()].
    */
    SQLITE_API const char* sqlite3_sql(sqlite3_stmt* pStmt);
    SQLITE_API char* sqlite3_expanded_sql(sqlite3_stmt* pStmt);
    SQLITE_API const char* sqlite3_normalized_sql(sqlite3_stmt* pStmt);

    /*
    ** CAPI3REF: Determine If An SQL Statement Writes The Database
    ** METHOD: sqlite3_stmt
    **
    ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
    ** and only if the [prepared statement] X makes no direct changes to
    ** the content of the database file.
    **
    ** Note that [application-defined SQL functions] or
    ** [virtual tables] might change the database indirectly as a side effect.
    ** ^(For example, if an application defines a function "eval()" that
    ** calls [sqlite3_exec()], then the following SQL statement would
    ** change the database file through side-effects:
    **
    ** <blockquote><pre>
    **    SELECT eval('DELETE FROM t1') FROM t2;
    ** </pre></blockquote>
    **
    ** But because the [SELECT] statement does not change the database file
    ** directly, sqlite3_stmt_readonly() would still return true.)^
    **
    ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
    ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
    ** since the statements themselves do not actually modify the database but
    ** rather they control the timing of when other statements modify the
    ** database.  ^The [ATTACH] and [DETACH] statements also cause
    ** sqlite3_stmt_readonly() to return true since, while those statements
    ** change the configuration of a database connection, they do not make
    ** changes to the content of the database files on disk.
    ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since
    ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and
    ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so
    ** sqlite3_stmt_readonly() returns false for those commands.
    */
    SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt* pStmt);

    /*
    ** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement
    ** METHOD: sqlite3_stmt
    **
    ** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the
    ** prepared statement S is an EXPLAIN statement, or 2 if the
    ** statement S is an EXPLAIN QUERY PLAN.
    ** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is
    ** an ordinary statement or a NULL pointer.
    */
    SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt* pStmt);

    /*
    ** CAPI3REF: Determine If A Prepared Statement Has Been Reset
    ** METHOD: sqlite3_stmt
    **
    ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
    ** [prepared statement] S has been stepped at least once using
    ** [sqlite3_step(S)] but has neither run to completion (returned
    ** [SQLITE_DONE] from [sqlite3_step(S)]) nor
    ** been reset using [sqlite3_reset(S)].  ^The sqlite3_stmt_busy(S)
    ** interface returns false if S is a NULL pointer.  If S is not a
    ** NULL pointer and is not a pointer to a valid [prepared statement]
    ** object, then the behavior is undefined and probably undesirable.
    **
    ** This interface can be used in combination [sqlite3_next_stmt()]
    ** to locate all prepared statements associated with a database
    ** connection that are in need of being reset.  This can be used,
    ** for example, in diagnostic routines to search for prepared
    ** statements that are holding a transaction open.
    */
    SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);

    /*
    ** CAPI3REF: Dynamically Typed Value Object
    ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
    **
    ** SQLite uses the sqlite3_value object to represent all values
    ** that can be stored in a database table. SQLite uses dynamic typing
    ** for the values it stores.  ^Values stored in sqlite3_value objects
    ** can be integers, floating point values, strings, BLOBs, or NULL.
    **
    ** An sqlite3_value object may be either "protected" or "unprotected".
    ** Some interfaces require a protected sqlite3_value.  Other interfaces
    ** will accept either a protected or an unprotected sqlite3_value.
    ** Every interface that accepts sqlite3_value arguments specifies
    ** whether or not it requires a protected sqlite3_value.  The
    ** [sqlite3_value_dup()] interface can be used to construct a new
    ** protected sqlite3_value from an unprotected sqlite3_value.
    **
    ** The terms "protected" and "unprotected" refer to whether or not
    ** a mutex is held.  An internal mutex is held for a protected
    ** sqlite3_value object but no mutex is held for an unprotected
    ** sqlite3_value object.  If SQLite is compiled to be single-threaded
    ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
    ** or if SQLite is run in one of reduced mutex modes
    ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
    ** then there is no distinction between protected and unprotected
    ** sqlite3_value objects and they can be used interchangeably.  However,
    ** for maximum code portability it is recommended that applications
    ** still make the distinction between protected and unprotected
    ** sqlite3_value objects even when not strictly required.
    **
    ** ^The sqlite3_value objects that are passed as parameters into the
    ** implementation of [application-defined SQL functions] are protected.
    ** ^The sqlite3_value object returned by
    ** [sqlite3_column_value()] is unprotected.
    ** Unprotected sqlite3_value objects may only be used as arguments
    ** to [sqlite3_result_value()], [sqlite3_bind_value()], and
    ** [sqlite3_value_dup()].
    ** The [sqlite3_value_blob | sqlite3_value_type()] family of
    ** interfaces require protected sqlite3_value objects.
    */
    typedef struct sqlite3_value sqlite3_value;

    /*
    ** CAPI3REF: SQL Function Context Object
    **
    ** The context in which an SQL function executes is stored in an
    ** sqlite3_context object.  ^A pointer to an sqlite3_context object
    ** is always first parameter to [application-defined SQL functions].
    ** The application-defined SQL function implementation will pass this
    ** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
    ** [sqlite3_aggregate_context()], [sqlite3_user_data()],
    ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
    ** and/or [sqlite3_set_auxdata()].
    */
    typedef struct sqlite3_context sqlite3_context;

    /*
    ** CAPI3REF: Binding Values To Prepared Statements
    ** KEYWORDS: {host parameter} {host parameters} {host parameter name}
    ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
    ** METHOD: sqlite3_stmt
    **
    ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
    ** literals may be replaced by a [parameter] that matches one of following
    ** templates:
    **
    ** <ul>
    ** <li>  ?
    ** <li>  ?NNN
    ** <li>  :VVV
    ** <li>  @VVV
    ** <li>  $VVV
    ** </ul>
    **
    ** In the templates above, NNN represents an integer literal,
    ** and VVV represents an alphanumeric identifier.)^  ^The values of these
    ** parameters (also called "host parameter names" or "SQL parameters")
    ** can be set using the sqlite3_bind_*() routines defined here.
    **
    ** ^The first argument to the sqlite3_bind_*() routines is always
    ** a pointer to the [sqlite3_stmt] object returned from
    ** [sqlite3_prepare_v2()] or its variants.
    **
    ** ^The second argument is the index of the SQL parameter to be set.
    ** ^The leftmost SQL parameter has an index of 1.  ^When the same named
    ** SQL parameter is used more than once, second and subsequent
    ** occurrences have the same index as the first occurrence.
    ** ^The index for named parameters can be looked up using the
    ** [sqlite3_bind_parameter_index()] API if desired.  ^The index
    ** for "?NNN" parameters is the value of NNN.
    ** ^The NNN value must be between 1 and the [sqlite3_limit()]
    ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766).
    **
    ** ^The third argument is the value to bind to the parameter.
    ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
    ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
    ** is ignored and the end result is the same as sqlite3_bind_null().
    ** ^If the third parameter to sqlite3_bind_text() is not NULL, then
    ** it should be a pointer to well-formed UTF8 text.
    ** ^If the third parameter to sqlite3_bind_text16() is not NULL, then
    ** it should be a pointer to well-formed UTF16 text.
    ** ^If the third parameter to sqlite3_bind_text64() is not NULL, then
    ** it should be a pointer to a well-formed unicode string that is
    ** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16
    ** otherwise.
    **
    ** [[byte-order determination rules]] ^The byte-order of
    ** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF)
    ** found in first character, which is removed, or in the absence of a BOM
    ** the byte order is the native byte order of the host
    ** machine for sqlite3_bind_text16() or the byte order specified in
    ** the 6th parameter for sqlite3_bind_text64().)^
    ** ^If UTF16 input text contains invalid unicode
    ** characters, then SQLite might change those invalid characters
    ** into the unicode replacement character: U+FFFD.
    **
    ** ^(In those routines that have a fourth argument, its value is the
    ** number of bytes in the parameter.  To be clear: the value is the
    ** number of <u>bytes</u> in the value, not the number of characters.)^
    ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
    ** is negative, then the length of the string is
    ** the number of bytes up to the first zero terminator.
    ** If the fourth parameter to sqlite3_bind_blob() is negative, then
    ** the behavior is undefined.
    ** If a non-negative fourth parameter is provided to sqlite3_bind_text()
    ** or sqlite3_bind_text16() or sqlite3_bind_text64() then
    ** that parameter must be the byte offset
    ** where the NUL terminator would occur assuming the string were NUL
    ** terminated.  If any NUL characters occurs at byte offsets less than
    ** the value of the fourth parameter then the resulting string value will
    ** contain embedded NULs.  The result of expressions involving strings
    ** with embedded NULs is undefined.
    **
    ** ^The fifth argument to the BLOB and string binding interfaces
    ** is a destructor used to dispose of the BLOB or
    ** string after SQLite has finished with it.  ^The destructor is called
    ** to dispose of the BLOB or string even if the call to the bind API fails,
    ** except the destructor is not called if the third parameter is a NULL
    ** pointer or the fourth parameter is negative.
    ** ^If the fifth argument is
    ** the special value [SQLITE_STATIC], then SQLite assumes that the
    ** information is in static, unmanaged space and does not need to be freed.
    ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then
    ** SQLite makes its own private copy of the data immediately, before
    ** the sqlite3_bind_*() routine returns.
    **
    ** ^The sixth argument to sqlite3_bind_text64() must be one of
    ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]
    ** to specify the encoding of the text in the third parameter.  If
    ** the sixth argument to sqlite3_bind_text64() is not one of the
    ** allowed values shown above, or if the text encoding is different
    ** from the encoding specified by the sixth parameter, then the behavior
    ** is undefined.
    **
    ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
    ** is filled with zeroes.  ^A zeroblob uses a fixed amount of memory
    ** (just an integer to hold its size) while it is being processed.
    ** Zeroblobs are intended to serve as placeholders for BLOBs whose
    ** content is later written using
    ** [sqlite3_blob_open | incremental BLOB I/O] routines.
    ** ^A negative value for the zeroblob results in a zero-length BLOB.
    **
    ** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in
    ** [prepared statement] S to have an SQL value of NULL, but to also be
    ** associated with the pointer P of type T.  ^D is either a NULL pointer or
    ** a pointer to a destructor function for P. ^SQLite will invoke the
    ** destructor D with a single argument of P when it is finished using
    ** P.  The T parameter should be a static string, preferably a string
    ** literal. The sqlite3_bind_pointer() routine is part of the
    ** [pointer passing interface] added for SQLite 3.20.0.
    **
    ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
    ** for the [prepared statement] or with a prepared statement for which
    ** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
    ** then the call will return [SQLITE_MISUSE].  If any sqlite3_bind_()
    ** routine is passed a [prepared statement] that has been finalized, the
    ** result is undefined and probably harmful.
    **
    ** ^Bindings are not cleared by the [sqlite3_reset()] routine.
    ** ^Unbound parameters are interpreted as NULL.
    **
    ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
    ** [error code] if anything goes wrong.
    ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
    ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
    ** [SQLITE_MAX_LENGTH].
    ** ^[SQLITE_RANGE] is returned if the parameter
    ** index is out of range.  ^[SQLITE_NOMEM] is returned if malloc() fails.
    **
    ** See also: [sqlite3_bind_parameter_count()],
    ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
    */
    SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
    SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
        void(*)(void*));
    SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
    SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
    SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
    SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
    SQLITE_API int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int, void(*)(void*));
    SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
    SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
        void(*)(void*), unsigned char encoding);
    SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
    SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*, void(*)(void*));
    SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
    SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);

    /*
    ** CAPI3REF: Number Of SQL Parameters
    ** METHOD: sqlite3_stmt
    **
    ** ^This routine can be used to find the number of [SQL parameters]
    ** in a [prepared statement].  SQL parameters are tokens of the
    ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
    ** placeholders for values that are [sqlite3_bind_blob | bound]
    ** to the parameters at a later time.
    **
    ** ^(This routine actually returns the index of the largest (rightmost)
    ** parameter. For all forms except ?NNN, this will correspond to the
    ** number of unique parameters.  If parameters of the ?NNN form are used,
    ** there may be gaps in the list.)^
    **
    ** See also: [sqlite3_bind_blob|sqlite3_bind()],
    ** [sqlite3_bind_parameter_name()], and
    ** [sqlite3_bind_parameter_index()].
    */
    SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);

    /*
    ** CAPI3REF: Name Of A Host Parameter
    ** METHOD: sqlite3_stmt
    **
    ** ^The sqlite3_bind_parameter_name(P,N) interface returns
    ** the name of the N-th [SQL parameter] in the [prepared statement] P.
    ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
    ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
    ** respectively.
    ** In other words, the initial ":" or "$" or "@" or "?"
    ** is included as part of the name.)^
    ** ^Parameters of the form "?" without a following integer have no name
    ** and are referred to as "nameless" or "anonymous parameters".
    **
    ** ^The first host parameter has an index of 1, not 0.
    **
    ** ^If the value N is out of range or if the N-th parameter is
    ** nameless, then NULL is returned.  ^The returned string is
    ** always in UTF-8 encoding even if the named parameter was
    ** originally specified as UTF-16 in [sqlite3_prepare16()],
    ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
    **
    ** See also: [sqlite3_bind_blob|sqlite3_bind()],
    ** [sqlite3_bind_parameter_count()], and
    ** [sqlite3_bind_parameter_index()].
    */
    SQLITE_API const char* sqlite3_bind_parameter_name(sqlite3_stmt*, int);

    /*
    ** CAPI3REF: Index Of A Parameter With A Given Name
    ** METHOD: sqlite3_stmt
    **
    ** ^Return the index of an SQL parameter given its name.  ^The
    ** index value returned is suitable for use as the second
    ** parameter to [sqlite3_bind_blob|sqlite3_bind()].  ^A zero
    ** is returned if no matching parameter is found.  ^The parameter
    ** name must be given in UTF-8 even if the original statement
    ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or
    ** [sqlite3_prepare16_v3()].
    **
    ** See also: [sqlite3_bind_blob|sqlite3_bind()],
    ** [sqlite3_bind_parameter_count()], and
    ** [sqlite3_bind_parameter_name()].
    */
    SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char* zName);

    /*
    ** CAPI3REF: Reset All Bindings On A Prepared Statement
    ** METHOD: sqlite3_stmt
    **
    ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
    ** the [sqlite3_bind_blob | bindings] on a [prepared statement].
    ** ^Use this routine to reset all host parameters to NULL.
    */
    SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);

    /*
    ** CAPI3REF: Number Of Columns In A Result Set
    ** METHOD: sqlite3_stmt
    **
    ** ^Return the number of columns in the result set returned by the
    ** [prepared statement]. ^If this routine returns 0, that means the
    ** [prepared statement] returns no data (for example an [UPDATE]).
    ** ^However, just because this routine returns a positive number does not
    ** mean that one or more rows of data will be returned.  ^A SELECT statement
    ** will always have a positive sqlite3_column_count() but depending on the
    ** WHERE clause constraints and the table content, it might return no rows.
    **
    ** See also: [sqlite3_data_count()]
    */
    SQLITE_API int sqlite3_column_count(sqlite3_stmt* pStmt);

    /*
    ** CAPI3REF: Column Names In A Result Set
    ** METHOD: sqlite3_stmt
    **
    ** ^These routines return the name assigned to a particular column
    ** in the result set of a [SELECT] statement.  ^The sqlite3_column_name()
    ** interface returns a pointer to a zero-terminated UTF-8 string
    ** and sqlite3_column_name16() returns a pointer to a zero-terminated
    ** UTF-16 string.  ^The first parameter is the [prepared statement]
    ** that implements the [SELECT] statement. ^The second parameter is the
    ** column number.  ^The leftmost column is number 0.
    **
    ** ^The returned string pointer is valid until either the [prepared statement]
    ** is destroyed by [sqlite3_finalize()] or until the statement is automatically
    ** reprepared by the first call to [sqlite3_step()] for a particular run
    ** or until the next call to
    ** sqlite3_column_name() or sqlite3_column_name16() on the same column.
    **
    ** ^If sqlite3_malloc() fails during the processing of either routine
    ** (for example during a conversion from UTF-8 to UTF-16) then a
    ** NULL pointer is returned.
    **
    ** ^The name of a result column is the value of the "AS" clause for
    ** that column, if there is an AS clause.  If there is no AS clause
    ** then the name of the column is unspecified and may change from
    ** one release of SQLite to the next.
    */
    SQLITE_API const char* sqlite3_column_name(sqlite3_stmt*, int N);
    SQLITE_API const void* sqlite3_column_name16(sqlite3_stmt*, int N);

    /*
    ** CAPI3REF: Source Of Data In A Query Result
    ** METHOD: sqlite3_stmt
    **
    ** ^These routines provide a means to determine the database, table, and
    ** table column that is the origin of a particular result column in
    ** [SELECT] statement.
    ** ^The name of the database or table or column can be returned as
    ** either a UTF-8 or UTF-16 string.  ^The _database_ routines return
    ** the database name, the _table_ routines return the table name, and
    ** the origin_ routines return the column name.
    ** ^The returned string is valid until the [prepared statement] is destroyed
    ** using [sqlite3_finalize()] or until the statement is automatically
    ** reprepared by the first call to [sqlite3_step()] for a particular run
    ** or until the same information is requested
    ** again in a different encoding.
    **
    ** ^The names returned are the original un-aliased names of the
    ** database, table, and column.
    **
    ** ^The first argument to these interfaces is a [prepared statement].
    ** ^These functions return information about the Nth result column returned by
    ** the statement, where N is the second function argument.
    ** ^The left-most column is column 0 for these routines.
    **
    ** ^If the Nth column returned by the statement is an expression or
    ** subquery and is not a column value, then all of these functions return
    ** NULL.  ^These routines might also return NULL if a memory allocation error
    ** occurs.  ^Otherwise, they return the name of the attached database, table,
    ** or column that query result column was extracted from.
    **
    ** ^As with all other SQLite APIs, those whose names end with "16" return
    ** UTF-16 encoded strings and the other functions return UTF-8.
    **
    ** ^These APIs are only available if the library was compiled with the
    ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
    **
    ** If two or more threads call one or more
    ** [sqlite3_column_database_name | column metadata interfaces]
    ** for the same [prepared statement] and result column
    ** at the same time then the results are undefined.
    */
    SQLITE_API const char* sqlite3_column_database_name(sqlite3_stmt*, int);
    SQLITE_API const void* sqlite3_column_database_name16(sqlite3_stmt*, int);
    SQLITE_API const char* sqlite3_column_table_name(sqlite3_stmt*, int);
    SQLITE_API const void* sqlite3_column_table_name16(sqlite3_stmt*, int);
    SQLITE_API const char* sqlite3_column_origin_name(sqlite3_stmt*, int);
    SQLITE_API const void* sqlite3_column_origin_name16(sqlite3_stmt*, int);

    /*
    ** CAPI3REF: Declared Datatype Of A Query Result
    ** METHOD: sqlite3_stmt
    **
    ** ^(The first parameter is a [prepared statement].
    ** If this statement is a [SELECT] statement and the Nth column of the
    ** returned result set of that [SELECT] is a table column (not an
    ** expression or subquery) then the declared type of the table
    ** column is returned.)^  ^If the Nth column of the result set is an
    ** expression or subquery, then a NULL pointer is returned.
    ** ^The returned string is always UTF-8 encoded.
    **
    ** ^(For example, given the database schema:
    **
    ** CREATE TABLE t1(c1 VARIANT);
    **
    ** and the following statement to be compiled:
    **
    ** SELECT c1 + 1, c1 FROM t1;
    **
    ** this routine would return the string "VARIANT" for the second result
    ** column (i==1), and a NULL pointer for the first result column (i==0).)^
    **
    ** ^SQLite uses dynamic run-time typing.  ^So just because a column
    ** is declared to contain a particular type does not mean that the
    ** data stored in that column is of the declared type.  SQLite is
    ** strongly typed, but the typing is dynamic not static.  ^Type
    ** is associated with individual values, not with the containers
    ** used to hold those values.
    */
    SQLITE_API const char* sqlite3_column_decltype(sqlite3_stmt*, int);
    SQLITE_API const void* sqlite3_column_decltype16(sqlite3_stmt*, int);

    /*
    ** CAPI3REF: Evaluate An SQL Statement
    ** METHOD: sqlite3_stmt
    **
    ** After a [prepared statement] has been prepared using any of
    ** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()],
    ** or [sqlite3_prepare16_v3()] or one of the legacy
    ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
    ** must be called one or more times to evaluate the statement.
    **
    ** The details of the behavior of the sqlite3_step() interface depend
    ** on whether the statement was prepared using the newer "vX" interfaces
    ** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()],
    ** [sqlite3_prepare16_v2()] or the older legacy
    ** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()].  The use of the
    ** new "vX" interface is recommended for new applications but the legacy
    ** interface will continue to be supported.
    **
    ** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
    ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
    ** ^With the "v2" interface, any of the other [result codes] or
    ** [extended result codes] might be returned as well.
    **
    ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
    ** database locks it needs to do its job.  ^If the statement is a [COMMIT]
    ** or occurs outside of an explicit transaction, then you can retry the
    ** statement.  If the statement is not a [COMMIT] and occurs within an
    ** explicit transaction then you should rollback the transaction before
    ** continuing.
    **
    ** ^[SQLITE_DONE] means that the statement has finished executing
    ** successfully.  sqlite3_step() should not be called again on this virtual
    ** machine without first calling [sqlite3_reset()] to reset the virtual
    ** machine back to its initial state.
    **
    ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
    ** is returned each time a new row of data is ready for processing by the
    ** caller. The values may be accessed using the [column access functions].
    ** sqlite3_step() is called again to retrieve the next row of data.
    **
    ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
    ** violation) has occurred.  sqlite3_step() should not be called again on
    ** the VM. More information may be found by calling [sqlite3_errmsg()].
    ** ^With the legacy interface, a more specific error code (for example,
    ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
    ** can be obtained by calling [sqlite3_reset()] on the
    ** [prepared statement].  ^In the "v2" interface,
    ** the more specific error code is returned directly by sqlite3_step().
    **
    ** [SQLITE_MISUSE] means that the this routine was called inappropriately.
    ** Perhaps it was called on a [prepared statement] that has
    ** already been [sqlite3_finalize | finalized] or on one that had
    ** previously returned [SQLITE_ERROR] or [SQLITE_DONE].  Or it could
    ** be the case that the same database connection is being used by two or
    ** more threads at the same moment in time.
    **
    ** For all versions of SQLite up to and including 3.6.23.1, a call to
    ** [sqlite3_reset()] was required after sqlite3_step() returned anything
    ** other than [SQLITE_ROW] before any subsequent invocation of
    ** sqlite3_step().  Failure to reset the prepared statement using
    ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
    ** sqlite3_step().  But after [version 3.6.23.1] ([dateof:3.6.23.1],
    ** sqlite3_step() began
    ** calling [sqlite3_reset()] automatically in this circumstance rather
    ** than returning [SQLITE_MISUSE].  This is not considered a compatibility
    ** break because any application that ever receives an SQLITE_MISUSE error
    ** is broken by definition.  The [SQLITE_OMIT_AUTORESET] compile-time option
    ** can be used to restore the legacy behavior.
    **
    ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
    ** API always returns a generic error code, [SQLITE_ERROR], following any
    ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE].  You must call
    ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
    ** specific [error codes] that better describes the error.
    ** We admit that this is a goofy design.  The problem has been fixed
    ** with the "v2" interface.  If you prepare all of your SQL statements
    ** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()]
    ** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead
    ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
    ** then the more specific [error codes] are returned directly
    ** by sqlite3_step().  The use of the "vX" interfaces is recommended.
    */
    SQLITE_API int sqlite3_step(sqlite3_stmt*);

    /*
    ** CAPI3REF: Number of columns in a result set
    ** METHOD: sqlite3_stmt
    **
    ** ^The sqlite3_data_count(P) interface returns the number of columns in the
    ** current row of the result set of [prepared statement] P.
    ** ^If prepared statement P does not have results ready to return
    ** (via calls to the [sqlite3_column_int | sqlite3_column()] family of
    ** interfaces) then sqlite3_data_count(P) returns 0.
    ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
    ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
    ** [sqlite3_step](P) returned [SQLITE_DONE].  ^The sqlite3_data_count(P)
    ** will return non-zero if previous call to [sqlite3_step](P) returned
    ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
    ** where it always returns zero since each step of that multi-step
    ** pragma returns 0 columns of data.
    **
    ** See also: [sqlite3_column_count()]
    */
    SQLITE_API int sqlite3_data_count(sqlite3_stmt* pStmt);

    /*
    ** CAPI3REF: Fundamental Datatypes
    ** KEYWORDS: SQLITE_TEXT
    **
    ** ^(Every value in SQLite has one of five fundamental datatypes:
    **
    ** <ul>
    ** <li> 64-bit signed integer
    ** <li> 64-bit IEEE floating point number
    ** <li> string
    ** <li> BLOB
    ** <li> NULL
    ** </ul>)^
    **
    ** These constants are codes for each of those types.
    **
    ** Note that the SQLITE_TEXT constant was also used in SQLite version 2
    ** for a completely different meaning.  Software that links against both
    ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
    ** SQLITE_TEXT.
    */
#define SQLITE_INTEGER  1
#define SQLITE_FLOAT    2
#define SQLITE_BLOB     4
#define SQLITE_NULL     5
#ifdef SQLITE_TEXT
# undef SQLITE_TEXT
#else
# define SQLITE_TEXT     3
#endif
#define SQLITE3_TEXT     3

    /*
    ** CAPI3REF: Result Values From A Query
    ** KEYWORDS: {column access functions}
    ** METHOD: sqlite3_stmt
    **
    ** <b>Summary:</b>
    ** <blockquote><table border=0 cellpadding=0 cellspacing=0>
    ** <tr><td><b>sqlite3_column_blob</b><td>&rarr;<td>BLOB result
    ** <tr><td><b>sqlite3_column_double</b><td>&rarr;<td>REAL result
    ** <tr><td><b>sqlite3_column_int</b><td>&rarr;<td>32-bit INTEGER result
    ** <tr><td><b>sqlite3_column_int64</b><td>&rarr;<td>64-bit INTEGER result
    ** <tr><td><b>sqlite3_column_text</b><td>&rarr;<td>UTF-8 TEXT result
    ** <tr><td><b>sqlite3_column_text16</b><td>&rarr;<td>UTF-16 TEXT result
    ** <tr><td><b>sqlite3_column_value</b><td>&rarr;<td>The result as an
    ** [sqlite3_value|unprotected sqlite3_value] object.
    ** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
    ** <tr><td><b>sqlite3_column_bytes</b><td>&rarr;<td>Size of a BLOB
    ** or a UTF-8 TEXT result in bytes
    ** <tr><td><b>sqlite3_column_bytes16&nbsp;&nbsp;</b>
    ** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
    ** TEXT in bytes
    ** <tr><td><b>sqlite3_column_type</b><td>&rarr;<td>Default
    ** datatype of the result
    ** </table></blockquote>
    **
    ** <b>Details:</b>
    **
    ** ^These routines return information about a single column of the current
    ** result row of a query.  ^In every case the first argument is a pointer
    ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
    ** that was returned from [sqlite3_prepare_v2()] or one of its variants)
    ** and the second argument is the index of the column for which information
    ** should be returned. ^The leftmost column of the result set has the index 0.
    ** ^The number of columns in the result can be determined using
    ** [sqlite3_column_count()].
    **
    ** If the SQL statement does not currently point to a valid row, or if the
    ** column index is out of range, the result is undefined.
    ** These routines may only be called when the most recent call to
    ** [sqlite3_step()] has returned [SQLITE_ROW] and neither
    ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
    ** If any of these routines are called after [sqlite3_reset()] or
    ** [sqlite3_finalize()] or after [sqlite3_step()] has returned
    ** something other than [SQLITE_ROW], the results are undefined.
    ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
    ** are called from a different thread while any of these routines
    ** are pending, then the results are undefined.
    **
    ** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16)
    ** each return the value of a result column in a specific data format.  If
    ** the result column is not initially in the requested format (for example,
    ** if the query returns an integer but the sqlite3_column_text() interface
    ** is used to extract the value) then an automatic type conversion is performed.
    **
    ** ^The sqlite3_column_type() routine returns the
    ** [SQLITE_INTEGER | datatype code] for the initial data type
    ** of the result column.  ^The returned value is one of [SQLITE_INTEGER],
    ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].
    ** The return value of sqlite3_column_type() can be used to decide which
    ** of the first six interface should be used to extract the column value.
    ** The value returned by sqlite3_column_type() is only meaningful if no
    ** automatic type conversions have occurred for the value in question.
    ** After a type conversion, the result of calling sqlite3_column_type()
    ** is undefined, though harmless.  Future
    ** versions of SQLite may change the behavior of sqlite3_column_type()
    ** following a type conversion.
    **
    ** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes()
    ** or sqlite3_column_bytes16() interfaces can be used to determine the size
    ** of that BLOB or string.
    **
    ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
    ** routine returns the number of bytes in that BLOB or string.
    ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
    ** the string to UTF-8 and then returns the number of bytes.
    ** ^If the result is a numeric value then sqlite3_column_bytes() uses
    ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
    ** the number of bytes in that string.
    ** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
    **
    ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
    ** routine returns the number of bytes in that BLOB or string.
    ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
    ** the string to UTF-16 and then returns the number of bytes.
    ** ^If the result is a numeric value then sqlite3_column_bytes16() uses
    ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
    ** the number of bytes in that string.
    ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
    **
    ** ^The values returned by [sqlite3_column_bytes()] and
    ** [sqlite3_column_bytes16()] do not include the zero terminators at the end
    ** of the string.  ^For clarity: the values returned by
    ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
    ** bytes in the string, not the number of characters.
    **
    ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
    ** even empty strings, are always zero-terminated.  ^The return
    ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
    **
    ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an
    ** [unprotected sqlite3_value] object.  In a multithreaded environment,
    ** an unprotected sqlite3_value object may only be used safely with
    ** [sqlite3_bind_value()] and [sqlite3_result_value()].
    ** If the [unprotected sqlite3_value] object returned by
    ** [sqlite3_column_value()] is used in any other way, including calls
    ** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
    ** or [sqlite3_value_bytes()], the behavior is not threadsafe.
    ** Hence, the sqlite3_column_value() interface
    ** is normally only useful within the implementation of
    ** [application-defined SQL functions] or [virtual tables], not within
    ** top-level application code.
    **
    ** The these routines may attempt to convert the datatype of the result.
    ** ^For example, if the internal representation is FLOAT and a text result
    ** is requested, [sqlite3_snprintf()] is used internally to perform the
    ** conversion automatically.  ^(The following table details the conversions
    ** that are applied:
    **
    ** <blockquote>
    ** <table border="1">
    ** <tr><th> Internal<br>Type <th> Requested<br>Type <th>  Conversion
    **
    ** <tr><td>  NULL    <td> INTEGER   <td> Result is 0
    ** <tr><td>  NULL    <td>  FLOAT    <td> Result is 0.0
    ** <tr><td>  NULL    <td>   TEXT    <td> Result is a NULL pointer
    ** <tr><td>  NULL    <td>   BLOB    <td> Result is a NULL pointer
    ** <tr><td> INTEGER  <td>  FLOAT    <td> Convert from integer to float
    ** <tr><td> INTEGER  <td>   TEXT    <td> ASCII rendering of the integer
    ** <tr><td> INTEGER  <td>   BLOB    <td> Same as INTEGER->TEXT
    ** <tr><td>  FLOAT   <td> INTEGER   <td> [CAST] to INTEGER
    ** <tr><td>  FLOAT   <td>   TEXT    <td> ASCII rendering of the float
    ** <tr><td>  FLOAT   <td>   BLOB    <td> [CAST] to BLOB
    ** <tr><td>  TEXT    <td> INTEGER   <td> [CAST] to INTEGER
    ** <tr><td>  TEXT    <td>  FLOAT    <td> [CAST] to REAL
    ** <tr><td>  TEXT    <td>   BLOB    <td> No change
    ** <tr><td>  BLOB    <td> INTEGER   <td> [CAST] to INTEGER
    ** <tr><td>  BLOB    <td>  FLOAT    <td> [CAST] to REAL
    ** <tr><td>  BLOB    <td>   TEXT    <td> Add a zero terminator if needed
    ** </table>
    ** </blockquote>)^
    **
    ** Note that when type conversions occur, pointers returned by prior
    ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
    ** sqlite3_column_text16() may be invalidated.
    ** Type conversions and pointer invalidations might occur
    ** in the following cases:
    **
    ** <ul>
    ** <li> The initial content is a BLOB and sqlite3_column_text() or
    **      sqlite3_column_text16() is called.  A zero-terminator might
    **      need to be added to the string.</li>
    ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
    **      sqlite3_column_text16() is called.  The content must be converted
    **      to UTF-16.</li>
    ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
    **      sqlite3_column_text() is called.  The content must be converted
    **      to UTF-8.</li>
    ** </ul>
    **
    ** ^Conversions between UTF-16be and UTF-16le are always done in place and do
    ** not invalidate a prior pointer, though of course the content of the buffer
    ** that the prior pointer references will have been modified.  Other kinds
    ** of conversion are done in place when it is possible, but sometimes they
    ** are not possible and in those cases prior pointers are invalidated.
    **
    ** The safest policy is to invoke these routines
    ** in one of the following ways:
    **
    ** <ul>
    **  <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
    **  <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
    **  <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
    ** </ul>
    **
    ** In other words, you should call sqlite3_column_text(),
    ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
    ** into the desired format, then invoke sqlite3_column_bytes() or
    ** sqlite3_column_bytes16() to find the size of the result.  Do not mix calls
    ** to sqlite3_column_text() or sqlite3_column_blob() with calls to
    ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
    ** with calls to sqlite3_column_bytes().
    **
    ** ^The pointers returned are valid until a type conversion occurs as
    ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
    ** [sqlite3_finalize()] is called.  ^The memory space used to hold strings
    ** and BLOBs is freed automatically.  Do not pass the pointers returned
    ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
    ** [sqlite3_free()].
    **
    ** As long as the input parameters are correct, these routines will only
    ** fail if an out-of-memory error occurs during a format conversion.
    ** Only the following subset of interfaces are subject to out-of-memory
    ** errors:
    **
    ** <ul>
    ** <li> sqlite3_column_blob()
    ** <li> sqlite3_column_text()
    ** <li> sqlite3_column_text16()
    ** <li> sqlite3_column_bytes()
    ** <li> sqlite3_column_bytes16()
    ** </ul>
    **
    ** If an out-of-memory error occurs, then the return value from these
    ** routines is the same as if the column had contained an SQL NULL value.
    ** Valid SQL NULL returns can be distinguished from out-of-memory errors
    ** by invoking the [sqlite3_errcode()] immediately after the suspect
    ** return value is obtained and before any
    ** other SQLite interface is called on the same [database connection].
    */
    SQLITE_API const void* sqlite3_column_blob(sqlite3_stmt*, int iCol);
    SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
    SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
    SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
    SQLITE_API const unsigned char* sqlite3_column_text(sqlite3_stmt*, int iCol);
    SQLITE_API const void* sqlite3_column_text16(sqlite3_stmt*, int iCol);
    SQLITE_API sqlite3_value* sqlite3_column_value(sqlite3_stmt*, int iCol);
    SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
    SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
    SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);

    /*
    ** CAPI3REF: Destroy A Prepared Statement Object
    ** DESTRUCTOR: sqlite3_stmt
    **
    ** ^The sqlite3_finalize() function is called to delete a [prepared statement].
    ** ^If the most recent evaluation of the statement encountered no errors
    ** or if the statement is never been evaluated, then sqlite3_finalize() returns
    ** SQLITE_OK.  ^If the most recent evaluation of statement S failed, then
    ** sqlite3_finalize(S) returns the appropriate [error code] or
    ** [extended error code].
    **
    ** ^The sqlite3_finalize(S) routine can be called at any point during
    ** the life cycle of [prepared statement] S:
    ** before statement S is ever evaluated, after
    ** one or more calls to [sqlite3_reset()], or after any call
    ** to [sqlite3_step()] regardless of whether or not the statement has
    ** completed execution.
    **
    ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
    **
    ** The application must finalize every [prepared statement] in order to avoid
    ** resource leaks.  It is a grievous error for the application to try to use
    ** a prepared statement after it has been finalized.  Any use of a prepared
    ** statement after it has been finalized can result in undefined and
    ** undesirable behavior such as segfaults and heap corruption.
    */
    SQLITE_API int sqlite3_finalize(sqlite3_stmt* pStmt);

    /*
    ** CAPI3REF: Reset A Prepared Statement Object
    ** METHOD: sqlite3_stmt
    **
    ** The sqlite3_reset() function is called to reset a [prepared statement]
    ** object back to its initial state, ready to be re-executed.
    ** ^Any SQL statement variables that had values bound to them using
    ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
    ** Use [sqlite3_clear_bindings()] to reset the bindings.
    **
    ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
    ** back to the beginning of its program.
    **
    ** ^If the most recent call to [sqlite3_step(S)] for the
    ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
    ** or if [sqlite3_step(S)] has never before been called on S,
    ** then [sqlite3_reset(S)] returns [SQLITE_OK].
    **
    ** ^If the most recent call to [sqlite3_step(S)] for the
    ** [prepared statement] S indicated an error, then
    ** [sqlite3_reset(S)] returns an appropriate [error code].
    **
    ** ^The [sqlite3_reset(S)] interface does not change the values
    ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
    */
    SQLITE_API int sqlite3_reset(sqlite3_stmt* pStmt);

    /*
    ** CAPI3REF: Create Or Redefine SQL Functions
    ** KEYWORDS: {function creation routines}
    ** METHOD: sqlite3
    **
    ** ^These functions (collectively known as "function creation routines")
    ** are used to add SQL functions or aggregates or to redefine the behavior
    ** of existing SQL functions or aggregates. The only differences between
    ** the three "sqlite3_create_function*" routines are the text encoding
    ** expected for the second parameter (the name of the function being
    ** created) and the presence or absence of a destructor callback for
    ** the application data pointer. Function sqlite3_create_window_function()
    ** is similar, but allows the user to supply the extra callback functions
    ** needed by [aggregate window functions].
    **
    ** ^The first parameter is the [database connection] to which the SQL
    ** function is to be added.  ^If an application uses more than one database
    ** connection then application-defined SQL functions must be added
    ** to each database connection separately.
    **
    ** ^The second parameter is the name of the SQL function to be created or
    ** redefined.  ^The length of the name is limited to 255 bytes in a UTF-8
    ** representation, exclusive of the zero-terminator.  ^Note that the name
    ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
    ** ^Any attempt to create a function with a longer name
    ** will result in [SQLITE_MISUSE] being returned.
    **
    ** ^The third parameter (nArg)
    ** is the number of arguments that the SQL function or
    ** aggregate takes. ^If this parameter is -1, then the SQL function or
    ** aggregate may take any number of arguments between 0 and the limit
    ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]).  If the third
    ** parameter is less than -1 or greater than 127 then the behavior is
    ** undefined.
    **
    ** ^The fourth parameter, eTextRep, specifies what
    ** [SQLITE_UTF8 | text encoding] this SQL function prefers for
    ** its parameters.  The application should set this parameter to
    ** [SQLITE_UTF16LE] if the function implementation invokes
    ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
    ** implementation invokes [sqlite3_value_text16be()] on an input, or
    ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
    ** otherwise.  ^The same SQL function may be registered multiple times using
    ** different preferred text encodings, with different implementations for
    ** each encoding.
    ** ^When multiple implementations of the same function are available, SQLite
    ** will pick the one that involves the least amount of data conversion.
    **
    ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
    ** to signal that the function will always return the same result given
    ** the same inputs within a single SQL statement.  Most SQL functions are
    ** deterministic.  The built-in [random()] SQL function is an example of a
    ** function that is not deterministic.  The SQLite query planner is able to
    ** perform additional optimizations on deterministic functions, so use
    ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
    **
    ** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY]
    ** flag, which if present prevents the function from being invoked from
    ** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions,
    ** index expressions, or the WHERE clause of partial indexes.
    **
    ** <span style="background-color:#ffff90;">
    ** For best security, the [SQLITE_DIRECTONLY] flag is recommended for
    ** all application-defined SQL functions that do not need to be
    ** used inside of triggers, view, CHECK constraints, or other elements of
    ** the database schema.  This flags is especially recommended for SQL
    ** functions that have side effects or reveal internal application state.
    ** Without this flag, an attacker might be able to modify the schema of
    ** a database file to include invocations of the function with parameters
    ** chosen by the attacker, which the application will then execute when
    ** the database file is opened and read.
    ** </span>
    **
    ** ^(The fifth parameter is an arbitrary pointer.  The implementation of the
    ** function can gain access to this pointer using [sqlite3_user_data()].)^
    **
    ** ^The sixth, seventh and eighth parameters passed to the three
    ** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are
    ** pointers to C-language functions that implement the SQL function or
    ** aggregate. ^A scalar SQL function requires an implementation of the xFunc
    ** callback only; NULL pointers must be passed as the xStep and xFinal
    ** parameters. ^An aggregate SQL function requires an implementation of xStep
    ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
    ** SQL function or aggregate, pass NULL pointers for all three function
    ** callbacks.
    **
    ** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue
    ** and xInverse) passed to sqlite3_create_window_function are pointers to
    ** C-language callbacks that implement the new function. xStep and xFinal
    ** must both be non-NULL. xValue and xInverse may either both be NULL, in
    ** which case a regular aggregate function is created, or must both be
    ** non-NULL, in which case the new function may be used as either an aggregate
    ** or aggregate window function. More details regarding the implementation
    ** of aggregate window functions are
    ** [user-defined window functions|available here].
    **
    ** ^(If the final parameter to sqlite3_create_function_v2() or
    ** sqlite3_create_window_function() is not NULL, then it is destructor for
    ** the application data pointer. The destructor is invoked when the function
    ** is deleted, either by being overloaded or when the database connection
    ** closes.)^ ^The destructor is also invoked if the call to
    ** sqlite3_create_function_v2() fails.  ^When the destructor callback is
    ** invoked, it is passed a single argument which is a copy of the application
    ** data pointer which was the fifth parameter to sqlite3_create_function_v2().
    **
    ** ^It is permitted to register multiple implementations of the same
    ** functions with the same name but with either differing numbers of
    ** arguments or differing preferred text encodings.  ^SQLite will use
    ** the implementation that most closely matches the way in which the
    ** SQL function is used.  ^A function implementation with a non-negative
    ** nArg parameter is a better match than a function implementation with
    ** a negative nArg.  ^A function where the preferred text encoding
    ** matches the database encoding is a better
    ** match than a function where the encoding is different.
    ** ^A function where the encoding difference is between UTF16le and UTF16be
    ** is a closer match than a function where the encoding difference is
    ** between UTF8 and UTF16.
    **
    ** ^Built-in functions may be overloaded by new application-defined functions.
    **
    ** ^An application-defined function is permitted to call other
    ** SQLite interfaces.  However, such calls must not
    ** close the database connection nor finalize or reset the prepared
    ** statement in which the function is running.
    */
    SQLITE_API int sqlite3_create_function(
        sqlite3* db,
        const char* zFunctionName,
        int nArg,
        int eTextRep,
        void* pApp,
        void (*xFunc)(sqlite3_context*, int, sqlite3_value**),
        void (*xStep)(sqlite3_context*, int, sqlite3_value**),
        void (*xFinal)(sqlite3_context*)
    );
    SQLITE_API int sqlite3_create_function16(
        sqlite3* db,
        const void* zFunctionName,
        int nArg,
        int eTextRep,
        void* pApp,
        void (*xFunc)(sqlite3_context*, int, sqlite3_value**),
        void (*xStep)(sqlite3_context*, int, sqlite3_value**),
        void (*xFinal)(sqlite3_context*)
    );
    SQLITE_API int sqlite3_create_function_v2(
        sqlite3* db,
        const char* zFunctionName,
        int nArg,
        int eTextRep,
        void* pApp,
        void (*xFunc)(sqlite3_context*, int, sqlite3_value**),
        void (*xStep)(sqlite3_context*, int, sqlite3_value**),
        void (*xFinal)(sqlite3_context*),
        void(*xDestroy)(void*)
    );
    SQLITE_API int sqlite3_create_window_function(
        sqlite3* db,
        const char* zFunctionName,
        int nArg,
        int eTextRep,
        void* pApp,
        void (*xStep)(sqlite3_context*, int, sqlite3_value**),
        void (*xFinal)(sqlite3_context*),
        void (*xValue)(sqlite3_context*),
        void (*xInverse)(sqlite3_context*, int, sqlite3_value**),
        void(*xDestroy)(void*)
    );

    /*
    ** CAPI3REF: Text Encodings
    **
    ** These constant define integer codes that represent the various
    ** text encodings supported by SQLite.
    */
#define SQLITE_UTF8           1    /* IMP: R-37514-35566 */
#define SQLITE_UTF16LE        2    /* IMP: R-03371-37637 */
#define SQLITE_UTF16BE        3    /* IMP: R-51971-34154 */
#define SQLITE_UTF16          4    /* Use native byte order */
#define SQLITE_ANY            5    /* Deprecated */
#define SQLITE_UTF16_ALIGNED  8    /* sqlite3_create_collation only */

    /*
    ** CAPI3REF: Function Flags
    **
    ** These constants may be ORed together with the
    ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
    ** to [sqlite3_create_function()], [sqlite3_create_function16()], or
    ** [sqlite3_create_function_v2()].
    **
    ** <dl>
    ** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd>
    ** The SQLITE_DETERMINISTIC flag means that the new function always gives
    ** the same output when the input parameters are the same.
    ** The [abs|abs() function] is deterministic, for example, but
    ** [randomblob|randomblob()] is not.  Functions must
    ** be deterministic in order to be used in certain contexts such as
    ** with the WHERE clause of [partial indexes] or in [generated columns].
    ** SQLite might also optimize deterministic functions by factoring them
    ** out of inner loops.
    ** </dd>
    **
    ** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd>
    ** The SQLITE_DIRECTONLY flag means that the function may only be invoked
    ** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in
    ** schema structures such as [CHECK constraints], [DEFAULT clauses],
    ** [expression indexes], [partial indexes], or [generated columns].
    ** The SQLITE_DIRECTONLY flags is a security feature which is recommended
    ** for all [application-defined SQL functions], and especially for functions
    ** that have side-effects or that could potentially leak sensitive
    ** information.
    ** </dd>
    **
    ** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd>
    ** The SQLITE_INNOCUOUS flag means that the function is unlikely
    ** to cause problems even if misused.  An innocuous function should have
    ** no side effects and should not depend on any values other than its
    ** input parameters. The [abs|abs() function] is an example of an
    ** innocuous function.
    ** The [load_extension() SQL function] is not innocuous because of its
    ** side effects.
    ** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not
    ** exactly the same.  The [random|random() function] is an example of a
    ** function that is innocuous but not deterministic.
    ** <p>Some heightened security settings
    ** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF])
    ** disable the use of SQL functions inside views and triggers and in
    ** schema structures such as [CHECK constraints], [DEFAULT clauses],
    ** [expression indexes], [partial indexes], and [generated columns] unless
    ** the function is tagged with SQLITE_INNOCUOUS.  Most built-in functions
    ** are innocuous.  Developers are advised to avoid using the
    ** SQLITE_INNOCUOUS flag for application-defined functions unless the
    ** function has been carefully audited and found to be free of potentially
    ** security-adverse side-effects and information-leaks.
    ** </dd>
    **
    ** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd>
    ** The SQLITE_SUBTYPE flag indicates to SQLite that a function may call
    ** [sqlite3_value_subtype()] to inspect the sub-types of its arguments.
    ** Specifying this flag makes no difference for scalar or aggregate user
    ** functions. However, if it is not specified for a user-defined window
    ** function, then any sub-types belonging to arguments passed to the window
    ** function may be discarded before the window function is called (i.e.
    ** sqlite3_value_subtype() will always return 0).
    ** </dd>
    ** </dl>
    */
#define SQLITE_DETERMINISTIC    0x000000800
#define SQLITE_DIRECTONLY       0x000080000
#define SQLITE_SUBTYPE          0x000100000
#define SQLITE_INNOCUOUS        0x000200000

    /*
    ** CAPI3REF: Deprecated Functions
    ** DEPRECATED
    **
    ** These functions are [deprecated].  In order to maintain
    ** backwards compatibility with older code, these functions continue
    ** to be supported.  However, new applications should avoid
    ** the use of these functions.  To encourage programmers to avoid
    ** these functions, we will not explain what they do.
    */
#ifndef SQLITE_OMIT_DEPRECATED
    SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
    SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
    SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
    SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
    SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
    SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*, sqlite3_int64, int),
        void*, sqlite3_int64);
#endif

    /*
    ** CAPI3REF: Obtaining SQL Values
    ** METHOD: sqlite3_value
    **
    ** <b>Summary:</b>
    ** <blockquote><table border=0 cellpadding=0 cellspacing=0>
    ** <tr><td><b>sqlite3_value_blob</b><td>&rarr;<td>BLOB value
    ** <tr><td><b>sqlite3_value_double</b><td>&rarr;<td>REAL value
    ** <tr><td><b>sqlite3_value_int</b><td>&rarr;<td>32-bit INTEGER value
    ** <tr><td><b>sqlite3_value_int64</b><td>&rarr;<td>64-bit INTEGER value
    ** <tr><td><b>sqlite3_value_pointer</b><td>&rarr;<td>Pointer value
    ** <tr><td><b>sqlite3_value_text</b><td>&rarr;<td>UTF-8 TEXT value
    ** <tr><td><b>sqlite3_value_text16</b><td>&rarr;<td>UTF-16 TEXT value in
    ** the native byteorder
    ** <tr><td><b>sqlite3_value_text16be</b><td>&rarr;<td>UTF-16be TEXT value
    ** <tr><td><b>sqlite3_value_text16le</b><td>&rarr;<td>UTF-16le TEXT value
    ** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
    ** <tr><td><b>sqlite3_value_bytes</b><td>&rarr;<td>Size of a BLOB
    ** or a UTF-8 TEXT in bytes
    ** <tr><td><b>sqlite3_value_bytes16&nbsp;&nbsp;</b>
    ** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
    ** TEXT in bytes
    ** <tr><td><b>sqlite3_value_type</b><td>&rarr;<td>Default
    ** datatype of the value
    ** <tr><td><b>sqlite3_value_numeric_type&nbsp;&nbsp;</b>
    ** <td>&rarr;&nbsp;&nbsp;<td>Best numeric datatype of the value
    ** <tr><td><b>sqlite3_value_nochange&nbsp;&nbsp;</b>
    ** <td>&rarr;&nbsp;&nbsp;<td>True if the column is unchanged in an UPDATE
    ** against a virtual table.
    ** <tr><td><b>sqlite3_value_frombind&nbsp;&nbsp;</b>
    ** <td>&rarr;&nbsp;&nbsp;<td>True if value originated from a [bound parameter]
    ** </table></blockquote>
    **
    ** <b>Details:</b>
    **
    ** These routines extract type, size, and content information from
    ** [protected sqlite3_value] objects.  Protected sqlite3_value objects
    ** are used to pass parameter information into the functions that
    ** implement [application-defined SQL functions] and [virtual tables].
    **
    ** These routines work only with [protected sqlite3_value] objects.
    ** Any attempt to use these routines on an [unprotected sqlite3_value]
    ** is not threadsafe.
    **
    ** ^These routines work just like the corresponding [column access functions]
    ** except that these routines take a single [protected sqlite3_value] object
    ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
    **
    ** ^The sqlite3_value_text16() interface extracts a UTF-16 string
    ** in the native byte-order of the host machine.  ^The
    ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
    ** extract UTF-16 strings as big-endian and little-endian respectively.
    **
    ** ^If [sqlite3_value] object V was initialized
    ** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)]
    ** and if X and Y are strings that compare equal according to strcmp(X,Y),
    ** then sqlite3_value_pointer(V,Y) will return the pointer P.  ^Otherwise,
    ** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer()
    ** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
    **
    ** ^(The sqlite3_value_type(V) interface returns the
    ** [SQLITE_INTEGER | datatype code] for the initial datatype of the
    ** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER],
    ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^
    ** Other interfaces might change the datatype for an sqlite3_value object.
    ** For example, if the datatype is initially SQLITE_INTEGER and
    ** sqlite3_value_text(V) is called to extract a text value for that
    ** integer, then subsequent calls to sqlite3_value_type(V) might return
    ** SQLITE_TEXT.  Whether or not a persistent internal datatype conversion
    ** occurs is undefined and may change from one release of SQLite to the next.
    **
    ** ^(The sqlite3_value_numeric_type() interface attempts to apply
    ** numeric affinity to the value.  This means that an attempt is
    ** made to convert the value to an integer or floating point.  If
    ** such a conversion is possible without loss of information (in other
    ** words, if the value is a string that looks like a number)
    ** then the conversion is performed.  Otherwise no conversion occurs.
    ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
    **
    ** ^Within the [xUpdate] method of a [virtual table], the
    ** sqlite3_value_nochange(X) interface returns true if and only if
    ** the column corresponding to X is unchanged by the UPDATE operation
    ** that the xUpdate method call was invoked to implement and if
    ** and the prior [xColumn] method call that was invoked to extracted
    ** the value for that column returned without setting a result (probably
    ** because it queried [sqlite3_vtab_nochange()] and found that the column
    ** was unchanging).  ^Within an [xUpdate] method, any value for which
    ** sqlite3_value_nochange(X) is true will in all other respects appear
    ** to be a NULL value.  If sqlite3_value_nochange(X) is invoked anywhere other
    ** than within an [xUpdate] method call for an UPDATE statement, then
    ** the return value is arbitrary and meaningless.
    **
    ** ^The sqlite3_value_frombind(X) interface returns non-zero if the
    ** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()]
    ** interfaces.  ^If X comes from an SQL literal value, or a table column,
    ** or an expression, then sqlite3_value_frombind(X) returns zero.
    **
    ** Please pay particular attention to the fact that the pointer returned
    ** from [sqlite3_value_blob()], [sqlite3_value_text()], or
    ** [sqlite3_value_text16()] can be invalidated by a subsequent call to
    ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
    ** or [sqlite3_value_text16()].
    **
    ** These routines must be called from the same thread as
    ** the SQL function that supplied the [sqlite3_value*] parameters.
    **
    ** As long as the input parameter is correct, these routines can only
    ** fail if an out-of-memory error occurs during a format conversion.
    ** Only the following subset of interfaces are subject to out-of-memory
    ** errors:
    **
    ** <ul>
    ** <li> sqlite3_value_blob()
    ** <li> sqlite3_value_text()
    ** <li> sqlite3_value_text16()
    ** <li> sqlite3_value_text16le()
    ** <li> sqlite3_value_text16be()
    ** <li> sqlite3_value_bytes()
    ** <li> sqlite3_value_bytes16()
    ** </ul>
    **
    ** If an out-of-memory error occurs, then the return value from these
    ** routines is the same as if the column had contained an SQL NULL value.
    ** Valid SQL NULL returns can be distinguished from out-of-memory errors
    ** by invoking the [sqlite3_errcode()] immediately after the suspect
    ** return value is obtained and before any
    ** other SQLite interface is called on the same [database connection].
    */
    SQLITE_API const void* sqlite3_value_blob(sqlite3_value*);
    SQLITE_API double sqlite3_value_double(sqlite3_value*);
    SQLITE_API int sqlite3_value_int(sqlite3_value*);
    SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
    SQLITE_API void* sqlite3_value_pointer(sqlite3_value*, const char*);
    SQLITE_API const unsigned char* sqlite3_value_text(sqlite3_value*);
    SQLITE_API const void* sqlite3_value_text16(sqlite3_value*);
    SQLITE_API const void* sqlite3_value_text16le(sqlite3_value*);
    SQLITE_API const void* sqlite3_value_text16be(sqlite3_value*);
    SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
    SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
    SQLITE_API int sqlite3_value_type(sqlite3_value*);
    SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
    SQLITE_API int sqlite3_value_nochange(sqlite3_value*);
    SQLITE_API int sqlite3_value_frombind(sqlite3_value*);

    /*
    ** CAPI3REF: Finding The Subtype Of SQL Values
    ** METHOD: sqlite3_value
    **
    ** The sqlite3_value_subtype(V) function returns the subtype for
    ** an [application-defined SQL function] argument V.  The subtype
    ** information can be used to pass a limited amount of context from
    ** one SQL function to another.  Use the [sqlite3_result_subtype()]
    ** routine to set the subtype for the return value of an SQL function.
    */
    SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*);

    /*
    ** CAPI3REF: Copy And Free SQL Values
    ** METHOD: sqlite3_value
    **
    ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
    ** object D and returns a pointer to that copy.  ^The [sqlite3_value] returned
    ** is a [protected sqlite3_value] object even if the input is not.
    ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a
    ** memory allocation fails.
    **
    ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object
    ** previously obtained from [sqlite3_value_dup()].  ^If V is a NULL pointer
    ** then sqlite3_value_free(V) is a harmless no-op.
    */
    SQLITE_API sqlite3_value* sqlite3_value_dup(const sqlite3_value*);
    SQLITE_API void sqlite3_value_free(sqlite3_value*);

    /*
    ** CAPI3REF: Obtain Aggregate Function Context
    ** METHOD: sqlite3_context
    **
    ** Implementations of aggregate SQL functions use this
    ** routine to allocate memory for storing their state.
    **
    ** ^The first time the sqlite3_aggregate_context(C,N) routine is called
    ** for a particular aggregate function, SQLite allocates
    ** N bytes of memory, zeroes out that memory, and returns a pointer
    ** to the new memory. ^On second and subsequent calls to
    ** sqlite3_aggregate_context() for the same aggregate function instance,
    ** the same buffer is returned.  Sqlite3_aggregate_context() is normally
    ** called once for each invocation of the xStep callback and then one
    ** last time when the xFinal callback is invoked.  ^(When no rows match
    ** an aggregate query, the xStep() callback of the aggregate function
    ** implementation is never called and xFinal() is called exactly once.
    ** In those cases, sqlite3_aggregate_context() might be called for the
    ** first time from within xFinal().)^
    **
    ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
    ** when first called if N is less than or equal to zero or if a memory
    ** allocate error occurs.
    **
    ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
    ** determined by the N parameter on first successful call.  Changing the
    ** value of N in any subsequent call to sqlite3_aggregate_context() within
    ** the same aggregate function instance will not resize the memory
    ** allocation.)^  Within the xFinal callback, it is customary to set
    ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
    ** pointless memory allocations occur.
    **
    ** ^SQLite automatically frees the memory allocated by
    ** sqlite3_aggregate_context() when the aggregate query concludes.
    **
    ** The first parameter must be a copy of the
    ** [sqlite3_context | SQL function context] that is the first parameter
    ** to the xStep or xFinal callback routine that implements the aggregate
    ** function.
    **
    ** This routine must be called from the same thread in which
    ** the aggregate SQL function is running.
    */
    SQLITE_API void* sqlite3_aggregate_context(sqlite3_context*, int nBytes);

    /*
    ** CAPI3REF: User Data For Functions
    ** METHOD: sqlite3_context
    **
    ** ^The sqlite3_user_data() interface returns a copy of
    ** the pointer that was the pUserData parameter (the 5th parameter)
    ** of the [sqlite3_create_function()]
    ** and [sqlite3_create_function16()] routines that originally
    ** registered the application defined function.
    **
    ** This routine must be called from the same thread in which
    ** the application-defined function is running.
    */
    SQLITE_API void* sqlite3_user_data(sqlite3_context*);

    /*
    ** CAPI3REF: Database Connection For Functions
    ** METHOD: sqlite3_context
    **
    ** ^The sqlite3_context_db_handle() interface returns a copy of
    ** the pointer to the [database connection] (the 1st parameter)
    ** of the [sqlite3_create_function()]
    ** and [sqlite3_create_function16()] routines that originally
    ** registered the application defined function.
    */
    SQLITE_API sqlite3* sqlite3_context_db_handle(sqlite3_context*);

    /*
    ** CAPI3REF: Function Auxiliary Data
    ** METHOD: sqlite3_context
    **
    ** These functions may be used by (non-aggregate) SQL functions to
    ** associate metadata with argument values. If the same value is passed to
    ** multiple invocations of the same SQL function during query execution, under
    ** some circumstances the associated metadata may be preserved.  An example
    ** of where this might be useful is in a regular-expression matching
    ** function. The compiled version of the regular expression can be stored as
    ** metadata associated with the pattern string.
    ** Then as long as the pattern string remains the same,
    ** the compiled regular expression can be reused on multiple
    ** invocations of the same function.
    **
    ** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata
    ** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument
    ** value to the application-defined function.  ^N is zero for the left-most
    ** function argument.  ^If there is no metadata
    ** associated with the function argument, the sqlite3_get_auxdata(C,N) interface
    ** returns a NULL pointer.
    **
    ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th
    ** argument of the application-defined function.  ^Subsequent
    ** calls to sqlite3_get_auxdata(C,N) return P from the most recent
    ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or
    ** NULL if the metadata has been discarded.
    ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
    ** SQLite will invoke the destructor function X with parameter P exactly
    ** once, when the metadata is discarded.
    ** SQLite is free to discard the metadata at any time, including: <ul>
    ** <li> ^(when the corresponding function parameter changes)^, or
    ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
    **      SQL statement)^, or
    ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same
    **       parameter)^, or
    ** <li> ^(during the original sqlite3_set_auxdata() call when a memory
    **      allocation error occurs.)^ </ul>
    **
    ** Note the last bullet in particular.  The destructor X in
    ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
    ** sqlite3_set_auxdata() interface even returns.  Hence sqlite3_set_auxdata()
    ** should be called near the end of the function implementation and the
    ** function implementation should not make any use of P after
    ** sqlite3_set_auxdata() has been called.
    **
    ** ^(In practice, metadata is preserved between function calls for
    ** function parameters that are compile-time constants, including literal
    ** values and [parameters] and expressions composed from the same.)^
    **
    ** The value of the N parameter to these interfaces should be non-negative.
    ** Future enhancements may make use of negative N values to define new
    ** kinds of function caching behavior.
    **
    ** These routines must be called from the same thread in which
    ** the SQL function is running.
    */
    SQLITE_API void* sqlite3_get_auxdata(sqlite3_context*, int N);
    SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));


    /*
    ** CAPI3REF: Constants Defining Special Destructor Behavior
    **
    ** These are special values for the destructor that is passed in as the
    ** final argument to routines like [sqlite3_result_blob()].  ^If the destructor
    ** argument is SQLITE_STATIC, it means that the content pointer is constant
    ** and will never change.  It does not need to be destroyed.  ^The
    ** SQLITE_TRANSIENT value means that the content will likely change in
    ** the near future and that SQLite should make its own private copy of
    ** the content before returning.
    **
    ** The typedef is necessary to work around problems in certain
    ** C++ compilers.
    */
    typedef void (*sqlite3_destructor_type)(void*);
#define SQLITE_STATIC      ((sqlite3_destructor_type)0)
#define SQLITE_TRANSIENT   ((sqlite3_destructor_type)-1)

    /*
    ** CAPI3REF: Setting The Result Of An SQL Function
    ** METHOD: sqlite3_context
    **
    ** These routines are used by the xFunc or xFinal callbacks that
    ** implement SQL functions and aggregates.  See
    ** [sqlite3_create_function()] and [sqlite3_create_function16()]
    ** for additional information.
    **
    ** These functions work very much like the [parameter binding] family of
    ** functions used to bind values to host parameters in prepared statements.
    ** Refer to the [SQL parameter] documentation for additional information.
    **
    ** ^The sqlite3_result_blob() interface sets the result from
    ** an application-defined function to be the BLOB whose content is pointed
    ** to by the second parameter and which is N bytes long where N is the
    ** third parameter.
    **
    ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N)
    ** interfaces set the result of the application-defined function to be
    ** a BLOB containing all zero bytes and N bytes in size.
    **
    ** ^The sqlite3_result_double() interface sets the result from
    ** an application-defined function to be a floating point value specified
    ** by its 2nd argument.
    **
    ** ^The sqlite3_result_error() and sqlite3_result_error16() functions
    ** cause the implemented SQL function to throw an exception.
    ** ^SQLite uses the string pointed to by the
    ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
    ** as the text of an error message.  ^SQLite interprets the error
    ** message string from sqlite3_result_error() as UTF-8. ^SQLite
    ** interprets the string from sqlite3_result_error16() as UTF-16 using
    ** the same [byte-order determination rules] as [sqlite3_bind_text16()].
    ** ^If the third parameter to sqlite3_result_error()
    ** or sqlite3_result_error16() is negative then SQLite takes as the error
    ** message all text up through the first zero character.
    ** ^If the third parameter to sqlite3_result_error() or
    ** sqlite3_result_error16() is non-negative then SQLite takes that many
    ** bytes (not characters) from the 2nd parameter as the error message.
    ** ^The sqlite3_result_error() and sqlite3_result_error16()
    ** routines make a private copy of the error message text before
    ** they return.  Hence, the calling function can deallocate or
    ** modify the text after they return without harm.
    ** ^The sqlite3_result_error_code() function changes the error code
    ** returned by SQLite as a result of an error in a function.  ^By default,
    ** the error code is SQLITE_ERROR.  ^A subsequent call to sqlite3_result_error()
    ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
    **
    ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
    ** error indicating that a string or BLOB is too long to represent.
    **
    ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
    ** error indicating that a memory allocation failed.
    **
    ** ^The sqlite3_result_int() interface sets the return value
    ** of the application-defined function to be the 32-bit signed integer
    ** value given in the 2nd argument.
    ** ^The sqlite3_result_int64() interface sets the return value
    ** of the application-defined function to be the 64-bit signed integer
    ** value given in the 2nd argument.
    **
    ** ^The sqlite3_result_null() interface sets the return value
    ** of the application-defined function to be NULL.
    **
    ** ^The sqlite3_result_text(), sqlite3_result_text16(),
    ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
    ** set the return value of the application-defined function to be
    ** a text string which is represented as UTF-8, UTF-16 native byte order,
    ** UTF-16 little endian, or UTF-16 big endian, respectively.
    ** ^The sqlite3_result_text64() interface sets the return value of an
    ** application-defined function to be a text string in an encoding
    ** specified by the fifth (and last) parameter, which must be one
    ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE].
    ** ^SQLite takes the text result from the application from
    ** the 2nd parameter of the sqlite3_result_text* interfaces.
    ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
    ** is negative, then SQLite takes result text from the 2nd parameter
    ** through the first zero character.
    ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
    ** is non-negative, then as many bytes (not characters) of the text
    ** pointed to by the 2nd parameter are taken as the application-defined
    ** function result.  If the 3rd parameter is non-negative, then it
    ** must be the byte offset into the string where the NUL terminator would
    ** appear if the string where NUL terminated.  If any NUL characters occur
    ** in the string at a byte offset that is less than the value of the 3rd
    ** parameter, then the resulting string will contain embedded NULs and the
    ** result of expressions operating on strings with embedded NULs is undefined.
    ** ^If the 4th parameter to the sqlite3_result_text* interfaces
    ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
    ** function as the destructor on the text or BLOB result when it has
    ** finished using that result.
    ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
    ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
    ** assumes that the text or BLOB result is in constant space and does not
    ** copy the content of the parameter nor call a destructor on the content
    ** when it has finished using that result.
    ** ^If the 4th parameter to the sqlite3_result_text* interfaces
    ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
    ** then SQLite makes a copy of the result into space obtained
    ** from [sqlite3_malloc()] before it returns.
    **
    ** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and
    ** sqlite3_result_text16be() routines, and for sqlite3_result_text64()
    ** when the encoding is not UTF8, if the input UTF16 begins with a
    ** byte-order mark (BOM, U+FEFF) then the BOM is removed from the
    ** string and the rest of the string is interpreted according to the
    ** byte-order specified by the BOM.  ^The byte-order specified by
    ** the BOM at the beginning of the text overrides the byte-order
    ** specified by the interface procedure.  ^So, for example, if
    ** sqlite3_result_text16le() is invoked with text that begins
    ** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the
    ** first two bytes of input are skipped and the remaining input
    ** is interpreted as UTF16BE text.
    **
    ** ^For UTF16 input text to the sqlite3_result_text16(),
    ** sqlite3_result_text16be(), sqlite3_result_text16le(), and
    ** sqlite3_result_text64() routines, if the text contains invalid
    ** UTF16 characters, the invalid characters might be converted
    ** into the unicode replacement character, U+FFFD.
    **
    ** ^The sqlite3_result_value() interface sets the result of
    ** the application-defined function to be a copy of the
    ** [unprotected sqlite3_value] object specified by the 2nd parameter.  ^The
    ** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
    ** so that the [sqlite3_value] specified in the parameter may change or
    ** be deallocated after sqlite3_result_value() returns without harm.
    ** ^A [protected sqlite3_value] object may always be used where an
    ** [unprotected sqlite3_value] object is required, so either
    ** kind of [sqlite3_value] object can be used with this interface.
    **
    ** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an
    ** SQL NULL value, just like [sqlite3_result_null(C)], except that it
    ** also associates the host-language pointer P or type T with that
    ** NULL value such that the pointer can be retrieved within an
    ** [application-defined SQL function] using [sqlite3_value_pointer()].
    ** ^If the D parameter is not NULL, then it is a pointer to a destructor
    ** for the P parameter.  ^SQLite invokes D with P as its only argument
    ** when SQLite is finished with P.  The T parameter should be a static
    ** string and preferably a string literal. The sqlite3_result_pointer()
    ** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
    **
    ** If these routines are called from within the different thread
    ** than the one containing the application-defined function that received
    ** the [sqlite3_context] pointer, the results are undefined.
    */
    SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
    SQLITE_API void sqlite3_result_blob64(sqlite3_context*, const void*,
        sqlite3_uint64, void(*)(void*));
    SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
    SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
    SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
    SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
    SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
    SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
    SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
    SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
    SQLITE_API void sqlite3_result_null(sqlite3_context*);
    SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
    SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*, sqlite3_uint64,
        void(*)(void*), unsigned char encoding);
    SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
    SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int, void(*)(void*));
    SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int, void(*)(void*));
    SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
    SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*, const char*, void(*)(void*));
    SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
    SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);


    /*
    ** CAPI3REF: Setting The Subtype Of An SQL Function
    ** METHOD: sqlite3_context
    **
    ** The sqlite3_result_subtype(C,T) function causes the subtype of
    ** the result from the [application-defined SQL function] with
    ** [sqlite3_context] C to be the value T.  Only the lower 8 bits
    ** of the subtype T are preserved in current versions of SQLite;
    ** higher order bits are discarded.
    ** The number of subtype bytes preserved by SQLite might increase
    ** in future releases of SQLite.
    */
    SQLITE_API void sqlite3_result_subtype(sqlite3_context*, unsigned int);

    /*
    ** CAPI3REF: Define New Collating Sequences
    ** METHOD: sqlite3
    **
    ** ^These functions add, remove, or modify a [collation] associated
    ** with the [database connection] specified as the first argument.
    **
    ** ^The name of the collation is a UTF-8 string
    ** for sqlite3_create_collation() and sqlite3_create_collation_v2()
    ** and a UTF-16 string in native byte order for sqlite3_create_collation16().
    ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
    ** considered to be the same name.
    **
    ** ^(The third argument (eTextRep) must be one of the constants:
    ** <ul>
    ** <li> [SQLITE_UTF8],
    ** <li> [SQLITE_UTF16LE],
    ** <li> [SQLITE_UTF16BE],
    ** <li> [SQLITE_UTF16], or
    ** <li> [SQLITE_UTF16_ALIGNED].
    ** </ul>)^
    ** ^The eTextRep argument determines the encoding of strings passed
    ** to the collating function callback, xCompare.
    ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
    ** force strings to be UTF16 with native byte order.
    ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
    ** on an even byte address.
    **
    ** ^The fourth argument, pArg, is an application data pointer that is passed
    ** through as the first argument to the collating function callback.
    **
    ** ^The fifth argument, xCompare, is a pointer to the collating function.
    ** ^Multiple collating functions can be registered using the same name but
    ** with different eTextRep parameters and SQLite will use whichever
    ** function requires the least amount of data transformation.
    ** ^If the xCompare argument is NULL then the collating function is
    ** deleted.  ^When all collating functions having the same name are deleted,
    ** that collation is no longer usable.
    **
    ** ^The collating function callback is invoked with a copy of the pArg
    ** application data pointer and with two strings in the encoding specified
    ** by the eTextRep argument.  The two integer parameters to the collating
    ** function callback are the length of the two strings, in bytes. The collating
    ** function must return an integer that is negative, zero, or positive
    ** if the first string is less than, equal to, or greater than the second,
    ** respectively.  A collating function must always return the same answer
    ** given the same inputs.  If two or more collating functions are registered
    ** to the same collation name (using different eTextRep values) then all
    ** must give an equivalent answer when invoked with equivalent strings.
    ** The collating function must obey the following properties for all
    ** strings A, B, and C:
    **
    ** <ol>
    ** <li> If A==B then B==A.
    ** <li> If A==B and B==C then A==C.
    ** <li> If A&lt;B THEN B&gt;A.
    ** <li> If A&lt;B and B&lt;C then A&lt;C.
    ** </ol>
    **
    ** If a collating function fails any of the above constraints and that
    ** collating function is registered and used, then the behavior of SQLite
    ** is undefined.
    **
    ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
    ** with the addition that the xDestroy callback is invoked on pArg when
    ** the collating function is deleted.
    ** ^Collating functions are deleted when they are overridden by later
    ** calls to the collation creation functions or when the
    ** [database connection] is closed using [sqlite3_close()].
    **
    ** ^The xDestroy callback is <u>not</u> called if the
    ** sqlite3_create_collation_v2() function fails.  Applications that invoke
    ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
    ** check the return code and dispose of the application data pointer
    ** themselves rather than expecting SQLite to deal with it for them.
    ** This is different from every other SQLite interface.  The inconsistency
    ** is unfortunate but cannot be changed without breaking backwards
    ** compatibility.
    **
    ** See also:  [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
    */
    SQLITE_API int sqlite3_create_collation(
        sqlite3*,
        const char* zName,
        int eTextRep,
        void* pArg,
        int(*xCompare)(void*, int, const void*, int, const void*)
    );
    SQLITE_API int sqlite3_create_collation_v2(
        sqlite3*,
        const char* zName,
        int eTextRep,
        void* pArg,
        int(*xCompare)(void*, int, const void*, int, const void*),
        void(*xDestroy)(void*)
    );
    SQLITE_API int sqlite3_create_collation16(
        sqlite3*,
        const void* zName,
        int eTextRep,
        void* pArg,
        int(*xCompare)(void*, int, const void*, int, const void*)
    );

    /*
    ** CAPI3REF: Collation Needed Callbacks
    ** METHOD: sqlite3
    **
    ** ^To avoid having to register all collation sequences before a database
    ** can be used, a single callback function may be registered with the
    ** [database connection] to be invoked whenever an undefined collation
    ** sequence is required.
    **
    ** ^If the function is registered using the sqlite3_collation_needed() API,
    ** then it is passed the names of undefined collation sequences as strings
    ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
    ** the names are passed as UTF-16 in machine native byte order.
    ** ^A call to either function replaces the existing collation-needed callback.
    **
    ** ^(When the callback is invoked, the first argument passed is a copy
    ** of the second argument to sqlite3_collation_needed() or
    ** sqlite3_collation_needed16().  The second argument is the database
    ** connection.  The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
    ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
    ** sequence function required.  The fourth parameter is the name of the
    ** required collation sequence.)^
    **
    ** The callback function should register the desired collation using
    ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
    ** [sqlite3_create_collation_v2()].
    */
    SQLITE_API int sqlite3_collation_needed(
        sqlite3*,
        void*,
        void(*)(void*, sqlite3*, int eTextRep, const char*)
    );
    SQLITE_API int sqlite3_collation_needed16(
        sqlite3*,
        void*,
        void(*)(void*, sqlite3*, int eTextRep, const void*)
    );

#ifdef SQLITE_ENABLE_CEROD
    /*
    ** Specify the activation key for a CEROD database.  Unless
    ** activated, none of the CEROD routines will work.
    */
    SQLITE_API void sqlite3_activate_cerod(
        const char* zPassPhrase        /* Activation phrase */
    );
#endif

    /*
    ** CAPI3REF: Suspend Execution For A Short Time
    **
    ** The sqlite3_sleep() function causes the current thread to suspend execution
    ** for at least a number of milliseconds specified in its parameter.
    **
    ** If the operating system does not support sleep requests with
    ** millisecond time resolution, then the time will be rounded up to
    ** the nearest second. The number of milliseconds of sleep actually
    ** requested from the operating system is returned.
    **
    ** ^SQLite implements this interface by calling the xSleep()
    ** method of the default [sqlite3_vfs] object.  If the xSleep() method
    ** of the default VFS is not implemented correctly, or not implemented at
    ** all, then the behavior of sqlite3_sleep() may deviate from the description
    ** in the previous paragraphs.
    */
    SQLITE_API int sqlite3_sleep(int);

    /*
    ** CAPI3REF: Name Of The Folder Holding Temporary Files
    **
    ** ^(If this global variable is made to point to a string which is
    ** the name of a folder (a.k.a. directory), then all temporary files
    ** created by SQLite when using a built-in [sqlite3_vfs | VFS]
    ** will be placed in that directory.)^  ^If this variable
    ** is a NULL pointer, then SQLite performs a search for an appropriate
    ** temporary file directory.
    **
    ** Applications are strongly discouraged from using this global variable.
    ** It is required to set a temporary folder on Windows Runtime (WinRT).
    ** But for all other platforms, it is highly recommended that applications
    ** neither read nor write this variable.  This global variable is a relic
    ** that exists for backwards compatibility of legacy applications and should
    ** be avoided in new projects.
    **
    ** It is not safe to read or modify this variable in more than one
    ** thread at a time.  It is not safe to read or modify this variable
    ** if a [database connection] is being used at the same time in a separate
    ** thread.
    ** It is intended that this variable be set once
    ** as part of process initialization and before any SQLite interface
    ** routines have been called and that this variable remain unchanged
    ** thereafter.
    **
    ** ^The [temp_store_directory pragma] may modify this variable and cause
    ** it to point to memory obtained from [sqlite3_malloc].  ^Furthermore,
    ** the [temp_store_directory pragma] always assumes that any string
    ** that this variable points to is held in memory obtained from
    ** [sqlite3_malloc] and the pragma may attempt to free that memory
    ** using [sqlite3_free].
    ** Hence, if this variable is modified directly, either it should be
    ** made NULL or made to point to memory obtained from [sqlite3_malloc]
    ** or else the use of the [temp_store_directory pragma] should be avoided.
    ** Except when requested by the [temp_store_directory pragma], SQLite
    ** does not free the memory that sqlite3_temp_directory points to.  If
    ** the application wants that memory to be freed, it must do
    ** so itself, taking care to only do so after all [database connection]
    ** objects have been destroyed.
    **
    ** <b>Note to Windows Runtime users:</b>  The temporary directory must be set
    ** prior to calling [sqlite3_open] or [sqlite3_open_v2].  Otherwise, various
    ** features that require the use of temporary files may fail.  Here is an
    ** example of how to do this using C++ with the Windows Runtime:
    **
    ** <blockquote><pre>
    ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
    ** &nbsp;     TemporaryFolder->Path->Data();
    ** char zPathBuf&#91;MAX_PATH + 1&#93;;
    ** memset(zPathBuf, 0, sizeof(zPathBuf));
    ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
    ** &nbsp;     NULL, NULL);
    ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
    ** </pre></blockquote>
    */
    SQLITE_API SQLITE_EXTERN char* sqlite3_temp_directory;

    /*
    ** CAPI3REF: Name Of The Folder Holding Database Files
    **
    ** ^(If this global variable is made to point to a string which is
    ** the name of a folder (a.k.a. directory), then all database files
    ** specified with a relative pathname and created or accessed by
    ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
    ** to be relative to that directory.)^ ^If this variable is a NULL
    ** pointer, then SQLite assumes that all database files specified
    ** with a relative pathname are relative to the current directory
    ** for the process.  Only the windows VFS makes use of this global
    ** variable; it is ignored by the unix VFS.
    **
    ** Changing the value of this variable while a database connection is
    ** open can result in a corrupt database.
    **
    ** It is not safe to read or modify this variable in more than one
    ** thread at a time.  It is not safe to read or modify this variable
    ** if a [database connection] is being used at the same time in a separate
    ** thread.
    ** It is intended that this variable be set once
    ** as part of process initialization and before any SQLite interface
    ** routines have been called and that this variable remain unchanged
    ** thereafter.
    **
    ** ^The [data_store_directory pragma] may modify this variable and cause
    ** it to point to memory obtained from [sqlite3_malloc].  ^Furthermore,
    ** the [data_store_directory pragma] always assumes that any string
    ** that this variable points to is held in memory obtained from
    ** [sqlite3_malloc] and the pragma may attempt to free that memory
    ** using [sqlite3_free].
    ** Hence, if this variable is modified directly, either it should be
    ** made NULL or made to point to memory obtained from [sqlite3_malloc]
    ** or else the use of the [data_store_directory pragma] should be avoided.
    */
    SQLITE_API SQLITE_EXTERN char* sqlite3_data_directory;

    /*
    ** CAPI3REF: Win32 Specific Interface
    **
    ** These interfaces are available only on Windows.  The
    ** [sqlite3_win32_set_directory] interface is used to set the value associated
    ** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to
    ** zValue, depending on the value of the type parameter.  The zValue parameter
    ** should be NULL to cause the previous value to be freed via [sqlite3_free];
    ** a non-NULL value will be copied into memory obtained from [sqlite3_malloc]
    ** prior to being used.  The [sqlite3_win32_set_directory] interface returns
    ** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported,
    ** or [SQLITE_NOMEM] if memory could not be allocated.  The value of the
    ** [sqlite3_data_directory] variable is intended to act as a replacement for
    ** the current directory on the sub-platforms of Win32 where that concept is
    ** not present, e.g. WinRT and UWP.  The [sqlite3_win32_set_directory8] and
    ** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the
    ** sqlite3_win32_set_directory interface except the string parameter must be
    ** UTF-8 or UTF-16, respectively.
    */
    SQLITE_API int sqlite3_win32_set_directory(
        unsigned long type, /* Identifier for directory being set or reset */
        void* zValue        /* New value for directory being set or reset */
    );
    SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char* zValue);
    SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void* zValue);

    /*
    ** CAPI3REF: Win32 Directory Types
    **
    ** These macros are only available on Windows.  They define the allowed values
    ** for the type argument to the [sqlite3_win32_set_directory] interface.
    */
#define SQLITE_WIN32_DATA_DIRECTORY_TYPE  1
#define SQLITE_WIN32_TEMP_DIRECTORY_TYPE  2

    /*
    ** CAPI3REF: Test For Auto-Commit Mode
    ** KEYWORDS: {autocommit mode}
    ** METHOD: sqlite3
    **
    ** ^The sqlite3_get_autocommit() interface returns non-zero or
    ** zero if the given database connection is or is not in autocommit mode,
    ** respectively.  ^Autocommit mode is on by default.
    ** ^Autocommit mode is disabled by a [BEGIN] statement.
    ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
    **
    ** If certain kinds of errors occur on a statement within a multi-statement
    ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
    ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
    ** transaction might be rolled back automatically.  The only way to
    ** find out whether SQLite automatically rolled back the transaction after
    ** an error is to use this function.
    **
    ** If another thread changes the autocommit status of the database
    ** connection while this routine is running, then the return value
    ** is undefined.
    */
    SQLITE_API int sqlite3_get_autocommit(sqlite3*);

    /*
    ** CAPI3REF: Find The Database Handle Of A Prepared Statement
    ** METHOD: sqlite3_stmt
    **
    ** ^The sqlite3_db_handle interface returns the [database connection] handle
    ** to which a [prepared statement] belongs.  ^The [database connection]
    ** returned by sqlite3_db_handle is the same [database connection]
    ** that was the first argument
    ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
    ** create the statement in the first place.
    */
    SQLITE_API sqlite3* sqlite3_db_handle(sqlite3_stmt*);

    /*
    ** CAPI3REF: Return The Filename For A Database Connection
    ** METHOD: sqlite3
    **
    ** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename
    ** associated with database N of connection D.
    ** ^If there is no attached database N on the database
    ** connection D, or if database N is a temporary or in-memory database, then
    ** this function will return either a NULL pointer or an empty string.
    **
    ** ^The string value returned by this routine is owned and managed by
    ** the database connection.  ^The value will be valid until the database N
    ** is [DETACH]-ed or until the database connection closes.
    **
    ** ^The filename returned by this function is the output of the
    ** xFullPathname method of the [VFS].  ^In other words, the filename
    ** will be an absolute pathname, even if the filename used
    ** to open the database originally was a URI or relative pathname.
    **
    ** If the filename pointer returned by this routine is not NULL, then it
    ** can be used as the filename input parameter to these routines:
    ** <ul>
    ** <li> [sqlite3_uri_parameter()]
    ** <li> [sqlite3_uri_boolean()]
    ** <li> [sqlite3_uri_int64()]
    ** <li> [sqlite3_filename_database()]
    ** <li> [sqlite3_filename_journal()]
    ** <li> [sqlite3_filename_wal()]
    ** </ul>
    */
    SQLITE_API const char* sqlite3_db_filename(sqlite3* db, const char* zDbName);

    /*
    ** CAPI3REF: Determine if a database is read-only
    ** METHOD: sqlite3
    **
    ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
    ** of connection D is read-only, 0 if it is read/write, or -1 if N is not
    ** the name of a database on connection D.
    */
    SQLITE_API int sqlite3_db_readonly(sqlite3* db, const char* zDbName);

    /*
    ** CAPI3REF: Determine the transaction state of a database
    ** METHOD: sqlite3
    **
    ** ^The sqlite3_txn_state(D,S) interface returns the current
    ** [transaction state] of schema S in database connection D.  ^If S is NULL,
    ** then the highest transaction state of any schema on database connection D
    ** is returned.  Transaction states are (in order of lowest to highest):
    ** <ol>
    ** <li value="0"> SQLITE_TXN_NONE
    ** <li value="1"> SQLITE_TXN_READ
    ** <li value="2"> SQLITE_TXN_WRITE
    ** </ol>
    ** ^If the S argument to sqlite3_txn_state(D,S) is not the name of
    ** a valid schema, then -1 is returned.
    */
    SQLITE_API int sqlite3_txn_state(sqlite3*, const char* zSchema);

    /*
    ** CAPI3REF: Allowed return values from [sqlite3_txn_state()]
    ** KEYWORDS: {transaction state}
    **
    ** These constants define the current transaction state of a database file.
    ** ^The [sqlite3_txn_state(D,S)] interface returns one of these
    ** constants in order to describe the transaction state of schema S
    ** in [database connection] D.
    **
    ** <dl>
    ** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt>
    ** <dd>The SQLITE_TXN_NONE state means that no transaction is currently
    ** pending.</dd>
    **
    ** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt>
    ** <dd>The SQLITE_TXN_READ state means that the database is currently
    ** in a read transaction.  Content has been read from the database file
    ** but nothing in the database file has changed.  The transaction state
    ** will advanced to SQLITE_TXN_WRITE if any changes occur and there are
    ** no other conflicting concurrent write transactions.  The transaction
    ** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or
    ** [COMMIT].</dd>
    **
    ** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt>
    ** <dd>The SQLITE_TXN_WRITE state means that the database is currently
    ** in a write transaction.  Content has been written to the database file
    ** but has not yet committed.  The transaction state will change to
    ** to SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd>
    */
#define SQLITE_TXN_NONE  0
#define SQLITE_TXN_READ  1
#define SQLITE_TXN_WRITE 2

    /*
    ** CAPI3REF: Find the next prepared statement
    ** METHOD: sqlite3
    **
    ** ^This interface returns a pointer to the next [prepared statement] after
    ** pStmt associated with the [database connection] pDb.  ^If pStmt is NULL
    ** then this interface returns a pointer to the first prepared statement
    ** associated with the database connection pDb.  ^If no prepared statement
    ** satisfies the conditions of this routine, it returns NULL.
    **
    ** The [database connection] pointer D in a call to
    ** [sqlite3_next_stmt(D,S)] must refer to an open database
    ** connection and in particular must not be a NULL pointer.
    */
    SQLITE_API sqlite3_stmt* sqlite3_next_stmt(sqlite3* pDb, sqlite3_stmt* pStmt);

    /*
    ** CAPI3REF: Commit And Rollback Notification Callbacks
    ** METHOD: sqlite3
    **
    ** ^The sqlite3_commit_hook() interface registers a callback
    ** function to be invoked whenever a transaction is [COMMIT | committed].
    ** ^Any callback set by a previous call to sqlite3_commit_hook()
    ** for the same database connection is overridden.
    ** ^The sqlite3_rollback_hook() interface registers a callback
    ** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
    ** ^Any callback set by a previous call to sqlite3_rollback_hook()
    ** for the same database connection is overridden.
    ** ^The pArg argument is passed through to the callback.
    ** ^If the callback on a commit hook function returns non-zero,
    ** then the commit is converted into a rollback.
    **
    ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
    ** return the P argument from the previous call of the same function
    ** on the same [database connection] D, or NULL for
    ** the first call for each function on D.
    **
    ** The commit and rollback hook callbacks are not reentrant.
    ** The callback implementation must not do anything that will modify
    ** the database connection that invoked the callback.  Any actions
    ** to modify the database connection must be deferred until after the
    ** completion of the [sqlite3_step()] call that triggered the commit
    ** or rollback hook in the first place.
    ** Note that running any other SQL statements, including SELECT statements,
    ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
    ** the database connections for the meaning of "modify" in this paragraph.
    **
    ** ^Registering a NULL function disables the callback.
    **
    ** ^When the commit hook callback routine returns zero, the [COMMIT]
    ** operation is allowed to continue normally.  ^If the commit hook
    ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
    ** ^The rollback hook is invoked on a rollback that results from a commit
    ** hook returning non-zero, just as it would be with any other rollback.
    **
    ** ^For the purposes of this API, a transaction is said to have been
    ** rolled back if an explicit "ROLLBACK" statement is executed, or
    ** an error or constraint causes an implicit rollback to occur.
    ** ^The rollback callback is not invoked if a transaction is
    ** automatically rolled back because the database connection is closed.
    **
    ** See also the [sqlite3_update_hook()] interface.
    */
    SQLITE_API void* sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
    SQLITE_API void* sqlite3_rollback_hook(sqlite3*, void(*)(void*), void*);

    /*
    ** CAPI3REF: Data Change Notification Callbacks
    ** METHOD: sqlite3
    **
    ** ^The sqlite3_update_hook() interface registers a callback function
    ** with the [database connection] identified by the first argument
    ** to be invoked whenever a row is updated, inserted or deleted in
    ** a [rowid table].
    ** ^Any callback set by a previous call to this function
    ** for the same database connection is overridden.
    **
    ** ^The second argument is a pointer to the function to invoke when a
    ** row is updated, inserted or deleted in a rowid table.
    ** ^The first argument to the callback is a copy of the third argument
    ** to sqlite3_update_hook().
    ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
    ** or [SQLITE_UPDATE], depending on the operation that caused the callback
    ** to be invoked.
    ** ^The third and fourth arguments to the callback contain pointers to the
    ** database and table name containing the affected row.
    ** ^The final callback parameter is the [rowid] of the row.
    ** ^In the case of an update, this is the [rowid] after the update takes place.
    **
    ** ^(The update hook is not invoked when internal system tables are
    ** modified (i.e. sqlite_sequence).)^
    ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
    **
    ** ^In the current implementation, the update hook
    ** is not invoked when conflicting rows are deleted because of an
    ** [ON CONFLICT | ON CONFLICT REPLACE] clause.  ^Nor is the update hook
    ** invoked when rows are deleted using the [truncate optimization].
    ** The exceptions defined in this paragraph might change in a future
    ** release of SQLite.
    **
    ** The update hook implementation must not do anything that will modify
    ** the database connection that invoked the update hook.  Any actions
    ** to modify the database connection must be deferred until after the
    ** completion of the [sqlite3_step()] call that triggered the update hook.
    ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
    ** database connections for the meaning of "modify" in this paragraph.
    **
    ** ^The sqlite3_update_hook(D,C,P) function
    ** returns the P argument from the previous call
    ** on the same [database connection] D, or NULL for
    ** the first call on D.
    **
    ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()],
    ** and [sqlite3_preupdate_hook()] interfaces.
    */
    SQLITE_API void* sqlite3_update_hook(
        sqlite3*,
        void(*)(void*, int, char const*, char const*, sqlite3_int64),
        void*
    );

    /*
    ** CAPI3REF: Enable Or Disable Shared Pager Cache
    **
    ** ^(This routine enables or disables the sharing of the database cache
    ** and schema data structures between [database connection | connections]
    ** to the same database. Sharing is enabled if the argument is true
    ** and disabled if the argument is false.)^
    **
    ** ^Cache sharing is enabled and disabled for an entire process.
    ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]).
    ** In prior versions of SQLite,
    ** sharing was enabled or disabled for each thread separately.
    **
    ** ^(The cache sharing mode set by this interface effects all subsequent
    ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
    ** Existing database connections continue to use the sharing mode
    ** that was in effect at the time they were opened.)^
    **
    ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
    ** successfully.  An [error code] is returned otherwise.)^
    **
    ** ^Shared cache is disabled by default. It is recommended that it stay
    ** that way.  In other words, do not use this routine.  This interface
    ** continues to be provided for historical compatibility, but its use is
    ** discouraged.  Any use of shared cache is discouraged.  If shared cache
    ** must be used, it is recommended that shared cache only be enabled for
    ** individual database connections using the [sqlite3_open_v2()] interface
    ** with the [SQLITE_OPEN_SHAREDCACHE] flag.
    **
    ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0
    ** and will always return SQLITE_MISUSE. On those systems,
    ** shared cache mode should be enabled per-database connection via
    ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE].
    **
    ** This interface is threadsafe on processors where writing a
    ** 32-bit integer is atomic.
    **
    ** See Also:  [SQLite Shared-Cache Mode]
    */
    SQLITE_API int sqlite3_enable_shared_cache(int);

    /*
    ** CAPI3REF: Attempt To Free Heap Memory
    **
    ** ^The sqlite3_release_memory() interface attempts to free N bytes
    ** of heap memory by deallocating non-essential memory allocations
    ** held by the database library.   Memory used to cache database
    ** pages to improve performance is an example of non-essential memory.
    ** ^sqlite3_release_memory() returns the number of bytes actually freed,
    ** which might be more or less than the amount requested.
    ** ^The sqlite3_release_memory() routine is a no-op returning zero
    ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
    **
    ** See also: [sqlite3_db_release_memory()]
    */
    SQLITE_API int sqlite3_release_memory(int);

    /*
    ** CAPI3REF: Free Memory Used By A Database Connection
    ** METHOD: sqlite3
    **
    ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
    ** memory as possible from database connection D. Unlike the
    ** [sqlite3_release_memory()] interface, this interface is in effect even
    ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
    ** omitted.
    **
    ** See also: [sqlite3_release_memory()]
    */
    SQLITE_API int sqlite3_db_release_memory(sqlite3*);

    /*
    ** CAPI3REF: Impose A Limit On Heap Size
    **
    ** These interfaces impose limits on the amount of heap memory that will be
    ** by all database connections within a single process.
    **
    ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
    ** soft limit on the amount of heap memory that may be allocated by SQLite.
    ** ^SQLite strives to keep heap memory utilization below the soft heap
    ** limit by reducing the number of pages held in the page cache
    ** as heap memory usages approaches the limit.
    ** ^The soft heap limit is "soft" because even though SQLite strives to stay
    ** below the limit, it will exceed the limit rather than generate
    ** an [SQLITE_NOMEM] error.  In other words, the soft heap limit
    ** is advisory only.
    **
    ** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of
    ** N bytes on the amount of memory that will be allocated.  ^The
    ** sqlite3_hard_heap_limit64(N) interface is similar to
    ** sqlite3_soft_heap_limit64(N) except that memory allocations will fail
    ** when the hard heap limit is reached.
    **
    ** ^The return value from both sqlite3_soft_heap_limit64() and
    ** sqlite3_hard_heap_limit64() is the size of
    ** the heap limit prior to the call, or negative in the case of an
    ** error.  ^If the argument N is negative
    ** then no change is made to the heap limit.  Hence, the current
    ** size of heap limits can be determined by invoking
    ** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1).
    **
    ** ^Setting the heap limits to zero disables the heap limiter mechanism.
    **
    ** ^The soft heap limit may not be greater than the hard heap limit.
    ** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N)
    ** is invoked with a value of N that is greater than the hard heap limit,
    ** the the soft heap limit is set to the value of the hard heap limit.
    ** ^The soft heap limit is automatically enabled whenever the hard heap
    ** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and
    ** the soft heap limit is outside the range of 1..N, then the soft heap
    ** limit is set to N.  ^Invoking sqlite3_soft_heap_limit64(0) when the
    ** hard heap limit is enabled makes the soft heap limit equal to the
    ** hard heap limit.
    **
    ** The memory allocation limits can also be adjusted using
    ** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit].
    **
    ** ^(The heap limits are not enforced in the current implementation
    ** if one or more of following conditions are true:
    **
    ** <ul>
    ** <li> The limit value is set to zero.
    ** <li> Memory accounting is disabled using a combination of the
    **      [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
    **      the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
    ** <li> An alternative page cache implementation is specified using
    **      [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
    ** <li> The page cache allocates from its own memory pool supplied
    **      by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
    **      from the heap.
    ** </ul>)^
    **
    ** The circumstances under which SQLite will enforce the heap limits may
    ** changes in future releases of SQLite.
    */
    SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
    SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N);

    /*
    ** CAPI3REF: Deprecated Soft Heap Limit Interface
    ** DEPRECATED
    **
    ** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
    ** interface.  This routine is provided for historical compatibility
    ** only.  All new applications should use the
    ** [sqlite3_soft_heap_limit64()] interface rather than this one.
    */
    SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);


    /*
    ** CAPI3REF: Extract Metadata About A Column Of A Table
    ** METHOD: sqlite3
    **
    ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns
    ** information about column C of table T in database D
    ** on [database connection] X.)^  ^The sqlite3_table_column_metadata()
    ** interface returns SQLITE_OK and fills in the non-NULL pointers in
    ** the final five arguments with appropriate values if the specified
    ** column exists.  ^The sqlite3_table_column_metadata() interface returns
    ** SQLITE_ERROR if the specified column does not exist.
    ** ^If the column-name parameter to sqlite3_table_column_metadata() is a
    ** NULL pointer, then this routine simply checks for the existence of the
    ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it
    ** does not.  If the table name parameter T in a call to
    ** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is
    ** undefined behavior.
    **
    ** ^The column is identified by the second, third and fourth parameters to
    ** this function. ^(The second parameter is either the name of the database
    ** (i.e. "main", "temp", or an attached database) containing the specified
    ** table or NULL.)^ ^If it is NULL, then all attached databases are searched
    ** for the table using the same algorithm used by the database engine to
    ** resolve unqualified table references.
    **
    ** ^The third and fourth parameters to this function are the table and column
    ** name of the desired column, respectively.
    **
    ** ^Metadata is returned by writing to the memory locations passed as the 5th
    ** and subsequent parameters to this function. ^Any of these arguments may be
    ** NULL, in which case the corresponding element of metadata is omitted.
    **
    ** ^(<blockquote>
    ** <table border="1">
    ** <tr><th> Parameter <th> Output<br>Type <th>  Description
    **
    ** <tr><td> 5th <td> const char* <td> Data type
    ** <tr><td> 6th <td> const char* <td> Name of default collation sequence
    ** <tr><td> 7th <td> int         <td> True if column has a NOT NULL constraint
    ** <tr><td> 8th <td> int         <td> True if column is part of the PRIMARY KEY
    ** <tr><td> 9th <td> int         <td> True if column is [AUTOINCREMENT]
    ** </table>
    ** </blockquote>)^
    **
    ** ^The memory pointed to by the character pointers returned for the
    ** declaration type and collation sequence is valid until the next
    ** call to any SQLite API function.
    **
    ** ^If the specified table is actually a view, an [error code] is returned.
    **
    ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table
    ** is not a [WITHOUT ROWID] table and an
    ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
    ** parameters are set for the explicitly declared column. ^(If there is no
    ** [INTEGER PRIMARY KEY] column, then the outputs
    ** for the [rowid] are set as follows:
    **
    ** <pre>
    **     data type: "INTEGER"
    **     collation sequence: "BINARY"
    **     not null: 0
    **     primary key: 1
    **     auto increment: 0
    ** </pre>)^
    **
    ** ^This function causes all database schemas to be read from disk and
    ** parsed, if that has not already been done, and returns an error if
    ** any errors are encountered while loading the schema.
    */
    SQLITE_API int sqlite3_table_column_metadata(
        sqlite3* db,                /* Connection handle */
        const char* zDbName,        /* Database name or NULL */
        const char* zTableName,     /* Table name */
        const char* zColumnName,    /* Column name */
        char const** pzDataType,    /* OUTPUT: Declared data type */
        char const** pzCollSeq,     /* OUTPUT: Collation sequence name */
        int* pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
        int* pPrimaryKey,           /* OUTPUT: True if column part of PK */
        int* pAutoinc               /* OUTPUT: True if column is auto-increment */
    );

    /*
    ** CAPI3REF: Load An Extension
    ** METHOD: sqlite3
    **
    ** ^This interface loads an SQLite extension library from the named file.
    **
    ** ^The sqlite3_load_extension() interface attempts to load an
    ** [SQLite extension] library contained in the file zFile.  If
    ** the file cannot be loaded directly, attempts are made to load
    ** with various operating-system specific extensions added.
    ** So for example, if "samplelib" cannot be loaded, then names like
    ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
    ** be tried also.
    **
    ** ^The entry point is zProc.
    ** ^(zProc may be 0, in which case SQLite will try to come up with an
    ** entry point name on its own.  It first tries "sqlite3_extension_init".
    ** If that does not work, it constructs a name "sqlite3_X_init" where the
    ** X is consists of the lower-case equivalent of all ASCII alphabetic
    ** characters in the filename from the last "/" to the first following
    ** "." and omitting any initial "lib".)^
    ** ^The sqlite3_load_extension() interface returns
    ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
    ** ^If an error occurs and pzErrMsg is not 0, then the
    ** [sqlite3_load_extension()] interface shall attempt to
    ** fill *pzErrMsg with error message text stored in memory
    ** obtained from [sqlite3_malloc()]. The calling function
    ** should free this memory by calling [sqlite3_free()].
    **
    ** ^Extension loading must be enabled using
    ** [sqlite3_enable_load_extension()] or
    ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL)
    ** prior to calling this API,
    ** otherwise an error will be returned.
    **
    ** <b>Security warning:</b> It is recommended that the
    ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this
    ** interface.  The use of the [sqlite3_enable_load_extension()] interface
    ** should be avoided.  This will keep the SQL function [load_extension()]
    ** disabled and prevent SQL injections from giving attackers
    ** access to extension loading capabilities.
    **
    ** See also the [load_extension() SQL function].
    */
    SQLITE_API int sqlite3_load_extension(
        sqlite3* db,          /* Load the extension into this database connection */
        const char* zFile,    /* Name of the shared library containing extension */
        const char* zProc,    /* Entry point.  Derived from zFile if 0 */
        char** pzErrMsg       /* Put error message here if not 0 */
    );

    /*
    ** CAPI3REF: Enable Or Disable Extension Loading
    ** METHOD: sqlite3
    **
    ** ^So as not to open security holes in older applications that are
    ** unprepared to deal with [extension loading], and as a means of disabling
    ** [extension loading] while evaluating user-entered SQL, the following API
    ** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
    **
    ** ^Extension loading is off by default.
    ** ^Call the sqlite3_enable_load_extension() routine with onoff==1
    ** to turn extension loading on and call it with onoff==0 to turn
    ** it back off again.
    **
    ** ^This interface enables or disables both the C-API
    ** [sqlite3_load_extension()] and the SQL function [load_extension()].
    ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..)
    ** to enable or disable only the C-API.)^
    **
    ** <b>Security warning:</b> It is recommended that extension loading
    ** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method
    ** rather than this interface, so the [load_extension()] SQL function
    ** remains disabled. This will prevent SQL injections from giving attackers
    ** access to extension loading capabilities.
    */
    SQLITE_API int sqlite3_enable_load_extension(sqlite3* db, int onoff);

    /*
    ** CAPI3REF: Automatically Load Statically Linked Extensions
    **
    ** ^This interface causes the xEntryPoint() function to be invoked for
    ** each new [database connection] that is created.  The idea here is that
    ** xEntryPoint() is the entry point for a statically linked [SQLite extension]
    ** that is to be automatically loaded into all new database connections.
    **
    ** ^(Even though the function prototype shows that xEntryPoint() takes
    ** no arguments and returns void, SQLite invokes xEntryPoint() with three
    ** arguments and expects an integer result as if the signature of the
    ** entry point where as follows:
    **
    ** <blockquote><pre>
    ** &nbsp;  int xEntryPoint(
    ** &nbsp;    sqlite3 *db,
    ** &nbsp;    const char **pzErrMsg,
    ** &nbsp;    const struct sqlite3_api_routines *pThunk
    ** &nbsp;  );
    ** </pre></blockquote>)^
    **
    ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
    ** point to an appropriate error message (obtained from [sqlite3_mprintf()])
    ** and return an appropriate [error code].  ^SQLite ensures that *pzErrMsg
    ** is NULL before calling the xEntryPoint().  ^SQLite will invoke
    ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns.  ^If any
    ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
    ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
    **
    ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
    ** on the list of automatic extensions is a harmless no-op. ^No entry point
    ** will be called more than once for each database connection that is opened.
    **
    ** See also: [sqlite3_reset_auto_extension()]
    ** and [sqlite3_cancel_auto_extension()]
    */
    SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void));

    /*
    ** CAPI3REF: Cancel Automatic Extension Loading
    **
    ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
    ** initialization routine X that was registered using a prior call to
    ** [sqlite3_auto_extension(X)].  ^The [sqlite3_cancel_auto_extension(X)]
    ** routine returns 1 if initialization routine X was successfully
    ** unregistered and it returns 0 if X was not on the list of initialization
    ** routines.
    */
    SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void));

    /*
    ** CAPI3REF: Reset Automatic Extension Loading
    **
    ** ^This interface disables all automatic extensions previously
    ** registered using [sqlite3_auto_extension()].
    */
    SQLITE_API void sqlite3_reset_auto_extension(void);

    /*
    ** The interface to the virtual-table mechanism is currently considered
    ** to be experimental.  The interface might change in incompatible ways.
    ** If this is a problem for you, do not use the interface at this time.
    **
    ** When the virtual-table mechanism stabilizes, we will declare the
    ** interface fixed, support it indefinitely, and remove this comment.
    */

    /*
    ** Structures used by the virtual table interface
    */
    typedef struct sqlite3_vtab sqlite3_vtab;
    typedef struct sqlite3_index_info sqlite3_index_info;
    typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
    typedef struct sqlite3_module sqlite3_module;

    /*
    ** CAPI3REF: Virtual Table Object
    ** KEYWORDS: sqlite3_module {virtual table module}
    **
    ** This structure, sometimes called a "virtual table module",
    ** defines the implementation of a [virtual table].
    ** This structure consists mostly of methods for the module.
    **
    ** ^A virtual table module is created by filling in a persistent
    ** instance of this structure and passing a pointer to that instance
    ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
    ** ^The registration remains valid until it is replaced by a different
    ** module or until the [database connection] closes.  The content
    ** of this structure must not change while it is registered with
    ** any database connection.
    */
    struct sqlite3_module {
        int iVersion;
        int (*xCreate)(sqlite3*, void* pAux,
            int argc, const char* const* argv,
            sqlite3_vtab** ppVTab, char**);
        int (*xConnect)(sqlite3*, void* pAux,
            int argc, const char* const* argv,
            sqlite3_vtab** ppVTab, char**);
        int (*xBestIndex)(sqlite3_vtab* pVTab, sqlite3_index_info*);
        int (*xDisconnect)(sqlite3_vtab* pVTab);
        int (*xDestroy)(sqlite3_vtab* pVTab);
        int (*xOpen)(sqlite3_vtab* pVTab, sqlite3_vtab_cursor** ppCursor);
        int (*xClose)(sqlite3_vtab_cursor*);
        int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char* idxStr,
            int argc, sqlite3_value** argv);
        int (*xNext)(sqlite3_vtab_cursor*);
        int (*xEof)(sqlite3_vtab_cursor*);
        int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
        int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64* pRowid);
        int (*xUpdate)(sqlite3_vtab*, int, sqlite3_value**, sqlite3_int64*);
        int (*xBegin)(sqlite3_vtab* pVTab);
        int (*xSync)(sqlite3_vtab* pVTab);
        int (*xCommit)(sqlite3_vtab* pVTab);
        int (*xRollback)(sqlite3_vtab* pVTab);
        int (*xFindFunction)(sqlite3_vtab* pVtab, int nArg, const char* zName,
            void (**pxFunc)(sqlite3_context*, int, sqlite3_value**),
            void** ppArg);
        int (*xRename)(sqlite3_vtab* pVtab, const char* zNew);
        /* The methods above are in version 1 of the sqlite_module object. Those
        ** below are for version 2 and greater. */
        int (*xSavepoint)(sqlite3_vtab* pVTab, int);
        int (*xRelease)(sqlite3_vtab* pVTab, int);
        int (*xRollbackTo)(sqlite3_vtab* pVTab, int);
        /* The methods above are in versions 1 and 2 of the sqlite_module object.
        ** Those below are for version 3 and greater. */
        int (*xShadowName)(const char*);
    };

    /*
    ** CAPI3REF: Virtual Table Indexing Information
    ** KEYWORDS: sqlite3_index_info
    **
    ** The sqlite3_index_info structure and its substructures is used as part
    ** of the [virtual table] interface to
    ** pass information into and receive the reply from the [xBestIndex]
    ** method of a [virtual table module].  The fields under **Inputs** are the
    ** inputs to xBestIndex and are read-only.  xBestIndex inserts its
    ** results into the **Outputs** fields.
    **
    ** ^(The aConstraint[] array records WHERE clause constraints of the form:
    **
    ** <blockquote>column OP expr</blockquote>
    **
    ** where OP is =, &lt;, &lt;=, &gt;, or &gt;=.)^  ^(The particular operator is
    ** stored in aConstraint[].op using one of the
    ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
    ** ^(The index of the column is stored in
    ** aConstraint[].iColumn.)^  ^(aConstraint[].usable is TRUE if the
    ** expr on the right-hand side can be evaluated (and thus the constraint
    ** is usable) and false if it cannot.)^
    **
    ** ^The optimizer automatically inverts terms of the form "expr OP column"
    ** and makes other simplifications to the WHERE clause in an attempt to
    ** get as many WHERE clause terms into the form shown above as possible.
    ** ^The aConstraint[] array only reports WHERE clause terms that are
    ** relevant to the particular virtual table being queried.
    **
    ** ^Information about the ORDER BY clause is stored in aOrderBy[].
    ** ^Each term of aOrderBy records a column of the ORDER BY clause.
    **
    ** The colUsed field indicates which columns of the virtual table may be
    ** required by the current scan. Virtual table columns are numbered from
    ** zero in the order in which they appear within the CREATE TABLE statement
    ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),
    ** the corresponding bit is set within the colUsed mask if the column may be
    ** required by SQLite. If the table has at least 64 columns and any column
    ** to the right of the first 63 is required, then bit 63 of colUsed is also
    ** set. In other words, column iCol may be required if the expression
    ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to
    ** non-zero.
    **
    ** The [xBestIndex] method must fill aConstraintUsage[] with information
    ** about what parameters to pass to xFilter.  ^If argvIndex>0 then
    ** the right-hand side of the corresponding aConstraint[] is evaluated
    ** and becomes the argvIndex-th entry in argv.  ^(If aConstraintUsage[].omit
    ** is true, then the constraint is assumed to be fully handled by the
    ** virtual table and might not be checked again by the byte code.)^ ^(The
    ** aConstraintUsage[].omit flag is an optimization hint. When the omit flag
    ** is left in its default setting of false, the constraint will always be
    ** checked separately in byte code.  If the omit flag is change to true, then
    ** the constraint may or may not be checked in byte code.  In other words,
    ** when the omit flag is true there is no guarantee that the constraint will
    ** not be checked again using byte code.)^
    **
    ** ^The idxNum and idxPtr values are recorded and passed into the
    ** [xFilter] method.
    ** ^[sqlite3_free()] is used to free idxPtr if and only if
    ** needToFreeIdxPtr is true.
    **
    ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
    ** the correct order to satisfy the ORDER BY clause so that no separate
    ** sorting step is required.
    **
    ** ^The estimatedCost value is an estimate of the cost of a particular
    ** strategy. A cost of N indicates that the cost of the strategy is similar
    ** to a linear scan of an SQLite table with N rows. A cost of log(N)
    ** indicates that the expense of the operation is similar to that of a
    ** binary search on a unique indexed field of an SQLite table with N rows.
    **
    ** ^The estimatedRows value is an estimate of the number of rows that
    ** will be returned by the strategy.
    **
    ** The xBestIndex method may optionally populate the idxFlags field with a
    ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag -
    ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite
    ** assumes that the strategy may visit at most one row.
    **
    ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
    ** SQLite also assumes that if a call to the xUpdate() method is made as
    ** part of the same statement to delete or update a virtual table row and the
    ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
    ** any database changes. In other words, if the xUpdate() returns
    ** SQLITE_CONSTRAINT, the database contents must be exactly as they were
    ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
    ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
    ** the xUpdate method are automatically rolled back by SQLite.
    **
    ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
    ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]).
    ** If a virtual table extension is
    ** used with an SQLite version earlier than 3.8.2, the results of attempting
    ** to read or write the estimatedRows field are undefined (but are likely
    ** to include crashing the application). The estimatedRows field should
    ** therefore only be used if [sqlite3_libversion_number()] returns a
    ** value greater than or equal to 3008002. Similarly, the idxFlags field
    ** was added for [version 3.9.0] ([dateof:3.9.0]).
    ** It may therefore only be used if
    ** sqlite3_libversion_number() returns a value greater than or equal to
    ** 3009000.
    */
    struct sqlite3_index_info {
        /* Inputs */
        int nConstraint;           /* Number of entries in aConstraint */
        struct sqlite3_index_constraint {
            int iColumn;              /* Column constrained.  -1 for ROWID */
            unsigned char op;         /* Constraint operator */
            unsigned char usable;     /* True if this constraint is usable */
            int iTermOffset;          /* Used internally - xBestIndex should ignore */
        } *aConstraint;            /* Table of WHERE clause constraints */
        int nOrderBy;              /* Number of terms in the ORDER BY clause */
        struct sqlite3_index_orderby {
            int iColumn;              /* Column number */
            unsigned char desc;       /* True for DESC.  False for ASC. */
        } *aOrderBy;               /* The ORDER BY clause */
        /* Outputs */
        struct sqlite3_index_constraint_usage {
            int argvIndex;           /* if >0, constraint is part of argv to xFilter */
            unsigned char omit;      /* Do not code a test for this constraint */
        } *aConstraintUsage;
        int idxNum;                /* Number used to identify the index */
        char* idxStr;              /* String, possibly obtained from sqlite3_malloc */
        int needToFreeIdxStr;      /* Free idxStr using sqlite3_free() if true */
        int orderByConsumed;       /* True if output is already ordered */
        double estimatedCost;           /* Estimated cost of using this index */
        /* Fields below are only available in SQLite 3.8.2 and later */
        sqlite3_int64 estimatedRows;    /* Estimated number of rows returned */
        /* Fields below are only available in SQLite 3.9.0 and later */
        int idxFlags;              /* Mask of SQLITE_INDEX_SCAN_* flags */
        /* Fields below are only available in SQLite 3.10.0 and later */
        sqlite3_uint64 colUsed;    /* Input: Mask of columns used by statement */
    };

    /*
    ** CAPI3REF: Virtual Table Scan Flags
    **
    ** Virtual table implementations are allowed to set the
    ** [sqlite3_index_info].idxFlags field to some combination of
    ** these bits.
    */
#define SQLITE_INDEX_SCAN_UNIQUE      1     /* Scan visits at most 1 row */

    /*
    ** CAPI3REF: Virtual Table Constraint Operator Codes
    **
    ** These macros define the allowed values for the
    ** [sqlite3_index_info].aConstraint[].op field.  Each value represents
    ** an operator that is part of a constraint term in the wHERE clause of
    ** a query that uses a [virtual table].
    */
#define SQLITE_INDEX_CONSTRAINT_EQ         2
#define SQLITE_INDEX_CONSTRAINT_GT         4
#define SQLITE_INDEX_CONSTRAINT_LE         8
#define SQLITE_INDEX_CONSTRAINT_LT        16
#define SQLITE_INDEX_CONSTRAINT_GE        32
#define SQLITE_INDEX_CONSTRAINT_MATCH     64
#define SQLITE_INDEX_CONSTRAINT_LIKE      65
#define SQLITE_INDEX_CONSTRAINT_GLOB      66
#define SQLITE_INDEX_CONSTRAINT_REGEXP    67
#define SQLITE_INDEX_CONSTRAINT_NE        68
#define SQLITE_INDEX_CONSTRAINT_ISNOT     69
#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70
#define SQLITE_INDEX_CONSTRAINT_ISNULL    71
#define SQLITE_INDEX_CONSTRAINT_IS        72
#define SQLITE_INDEX_CONSTRAINT_FUNCTION 150

    /*
    ** CAPI3REF: Register A Virtual Table Implementation
    ** METHOD: sqlite3
    **
    ** ^These routines are used to register a new [virtual table module] name.
    ** ^Module names must be registered before
    ** creating a new [virtual table] using the module and before using a
    ** preexisting [virtual table] for the module.
    **
    ** ^The module name is registered on the [database connection] specified
    ** by the first parameter.  ^The name of the module is given by the
    ** second parameter.  ^The third parameter is a pointer to
    ** the implementation of the [virtual table module].   ^The fourth
    ** parameter is an arbitrary client data pointer that is passed through
    ** into the [xCreate] and [xConnect] methods of the virtual table module
    ** when a new virtual table is be being created or reinitialized.
    **
    ** ^The sqlite3_create_module_v2() interface has a fifth parameter which
    ** is a pointer to a destructor for the pClientData.  ^SQLite will
    ** invoke the destructor function (if it is not NULL) when SQLite
    ** no longer needs the pClientData pointer.  ^The destructor will also
    ** be invoked if the call to sqlite3_create_module_v2() fails.
    ** ^The sqlite3_create_module()
    ** interface is equivalent to sqlite3_create_module_v2() with a NULL
    ** destructor.
    **
    ** ^If the third parameter (the pointer to the sqlite3_module object) is
    ** NULL then no new module is create and any existing modules with the
    ** same name are dropped.
    **
    ** See also: [sqlite3_drop_modules()]
    */
    SQLITE_API int sqlite3_create_module(
        sqlite3* db,               /* SQLite connection to register module with */
        const char* zName,         /* Name of the module */
        const sqlite3_module* p,   /* Methods for the module */
        void* pClientData          /* Client data for xCreate/xConnect */
    );
    SQLITE_API int sqlite3_create_module_v2(
        sqlite3* db,               /* SQLite connection to register module with */
        const char* zName,         /* Name of the module */
        const sqlite3_module* p,   /* Methods for the module */
        void* pClientData,         /* Client data for xCreate/xConnect */
        void(*xDestroy)(void*)     /* Module destructor function */
    );

    /*
    ** CAPI3REF: Remove Unnecessary Virtual Table Implementations
    ** METHOD: sqlite3
    **
    ** ^The sqlite3_drop_modules(D,L) interface removes all virtual
    ** table modules from database connection D except those named on list L.
    ** The L parameter must be either NULL or a pointer to an array of pointers
    ** to strings where the array is terminated by a single NULL pointer.
    ** ^If the L parameter is NULL, then all virtual table modules are removed.
    **
    ** See also: [sqlite3_create_module()]
    */
    SQLITE_API int sqlite3_drop_modules(
        sqlite3* db,                /* Remove modules from this connection */
        const char** azKeep         /* Except, do not remove the ones named here */
    );

    /*
    ** CAPI3REF: Virtual Table Instance Object
    ** KEYWORDS: sqlite3_vtab
    **
    ** Every [virtual table module] implementation uses a subclass
    ** of this object to describe a particular instance
    ** of the [virtual table].  Each subclass will
    ** be tailored to the specific needs of the module implementation.
    ** The purpose of this superclass is to define certain fields that are
    ** common to all module implementations.
    **
    ** ^Virtual tables methods can set an error message by assigning a
    ** string obtained from [sqlite3_mprintf()] to zErrMsg.  The method should
    ** take care that any prior string is freed by a call to [sqlite3_free()]
    ** prior to assigning a new string to zErrMsg.  ^After the error message
    ** is delivered up to the client application, the string will be automatically
    ** freed by sqlite3_free() and the zErrMsg field will be zeroed.
    */
    struct sqlite3_vtab {
        const sqlite3_module* pModule;  /* The module for this virtual table */
        int nRef;                       /* Number of open cursors */
        char* zErrMsg;                  /* Error message from sqlite3_mprintf() */
        /* Virtual table implementations will typically add additional fields */
    };

    /*
    ** CAPI3REF: Virtual Table Cursor Object
    ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
    **
    ** Every [virtual table module] implementation uses a subclass of the
    ** following structure to describe cursors that point into the
    ** [virtual table] and are used
    ** to loop through the virtual table.  Cursors are created using the
    ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
    ** by the [sqlite3_module.xClose | xClose] method.  Cursors are used
    ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
    ** of the module.  Each module implementation will define
    ** the content of a cursor structure to suit its own needs.
    **
    ** This superclass exists in order to define fields of the cursor that
    ** are common to all implementations.
    */
    struct sqlite3_vtab_cursor {
        sqlite3_vtab* pVtab;      /* Virtual table of this cursor */
        /* Virtual table implementations will typically add additional fields */
    };

    /*
    ** CAPI3REF: Declare The Schema Of A Virtual Table
    **
    ** ^The [xCreate] and [xConnect] methods of a
    ** [virtual table module] call this interface
    ** to declare the format (the names and datatypes of the columns) of
    ** the virtual tables they implement.
    */
    SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char* zSQL);

    /*
    ** CAPI3REF: Overload A Function For A Virtual Table
    ** METHOD: sqlite3
    **
    ** ^(Virtual tables can provide alternative implementations of functions
    ** using the [xFindFunction] method of the [virtual table module].
    ** But global versions of those functions
    ** must exist in order to be overloaded.)^
    **
    ** ^(This API makes sure a global version of a function with a particular
    ** name and number of parameters exists.  If no such function exists
    ** before this API is called, a new function is created.)^  ^The implementation
    ** of the new function always causes an exception to be thrown.  So
    ** the new function is not good for anything by itself.  Its only
    ** purpose is to be a placeholder function that can be overloaded
    ** by a [virtual table].
    */
    SQLITE_API int sqlite3_overload_function(sqlite3*, const char* zFuncName, int nArg);

    /*
    ** The interface to the virtual-table mechanism defined above (back up
    ** to a comment remarkably similar to this one) is currently considered
    ** to be experimental.  The interface might change in incompatible ways.
    ** If this is a problem for you, do not use the interface at this time.
    **
    ** When the virtual-table mechanism stabilizes, we will declare the
    ** interface fixed, support it indefinitely, and remove this comment.
    */

    /*
    ** CAPI3REF: A Handle To An Open BLOB
    ** KEYWORDS: {BLOB handle} {BLOB handles}
    **
    ** An instance of this object represents an open BLOB on which
    ** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
    ** ^Objects of this type are created by [sqlite3_blob_open()]
    ** and destroyed by [sqlite3_blob_close()].
    ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
    ** can be used to read or write small subsections of the BLOB.
    ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
    */
    typedef struct sqlite3_blob sqlite3_blob;

    /*
    ** CAPI3REF: Open A BLOB For Incremental I/O
    ** METHOD: sqlite3
    ** CONSTRUCTOR: sqlite3_blob
    **
    ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
    ** in row iRow, column zColumn, table zTable in database zDb;
    ** in other words, the same BLOB that would be selected by:
    **
    ** <pre>
    **     SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
    ** </pre>)^
    **
    ** ^(Parameter zDb is not the filename that contains the database, but
    ** rather the symbolic name of the database. For attached databases, this is
    ** the name that appears after the AS keyword in the [ATTACH] statement.
    ** For the main database file, the database name is "main". For TEMP
    ** tables, the database name is "temp".)^
    **
    ** ^If the flags parameter is non-zero, then the BLOB is opened for read
    ** and write access. ^If the flags parameter is zero, the BLOB is opened for
    ** read-only access.
    **
    ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored
    ** in *ppBlob. Otherwise an [error code] is returned and, unless the error
    ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided
    ** the API is not misused, it is always safe to call [sqlite3_blob_close()]
    ** on *ppBlob after this function it returns.
    **
    ** This function fails with SQLITE_ERROR if any of the following are true:
    ** <ul>
    **   <li> ^(Database zDb does not exist)^,
    **   <li> ^(Table zTable does not exist within database zDb)^,
    **   <li> ^(Table zTable is a WITHOUT ROWID table)^,
    **   <li> ^(Column zColumn does not exist)^,
    **   <li> ^(Row iRow is not present in the table)^,
    **   <li> ^(The specified column of row iRow contains a value that is not
    **         a TEXT or BLOB value)^,
    **   <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE
    **         constraint and the blob is being opened for read/write access)^,
    **   <li> ^([foreign key constraints | Foreign key constraints] are enabled,
    **         column zColumn is part of a [child key] definition and the blob is
    **         being opened for read/write access)^.
    ** </ul>
    **
    ** ^Unless it returns SQLITE_MISUSE, this function sets the
    ** [database connection] error code and message accessible via
    ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
    **
    ** A BLOB referenced by sqlite3_blob_open() may be read using the
    ** [sqlite3_blob_read()] interface and modified by using
    ** [sqlite3_blob_write()].  The [BLOB handle] can be moved to a
    ** different row of the same table using the [sqlite3_blob_reopen()]
    ** interface.  However, the column, table, or database of a [BLOB handle]
    ** cannot be changed after the [BLOB handle] is opened.
    **
    ** ^(If the row that a BLOB handle points to is modified by an
    ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
    ** then the BLOB handle is marked as "expired".
    ** This is true if any column of the row is changed, even a column
    ** other than the one the BLOB handle is open on.)^
    ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
    ** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
    ** ^(Changes written into a BLOB prior to the BLOB expiring are not
    ** rolled back by the expiration of the BLOB.  Such changes will eventually
    ** commit if the transaction continues to completion.)^
    **
    ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
    ** the opened blob.  ^The size of a blob may not be changed by this
    ** interface.  Use the [UPDATE] SQL command to change the size of a
    ** blob.
    **
    ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
    ** and the built-in [zeroblob] SQL function may be used to create a
    ** zero-filled blob to read or write using the incremental-blob interface.
    **
    ** To avoid a resource leak, every open [BLOB handle] should eventually
    ** be released by a call to [sqlite3_blob_close()].
    **
    ** See also: [sqlite3_blob_close()],
    ** [sqlite3_blob_reopen()], [sqlite3_blob_read()],
    ** [sqlite3_blob_bytes()], [sqlite3_blob_write()].
    */
    SQLITE_API int sqlite3_blob_open(
        sqlite3*,
        const char* zDb,
        const char* zTable,
        const char* zColumn,
        sqlite3_int64 iRow,
        int flags,
        sqlite3_blob** ppBlob
    );

    /*
    ** CAPI3REF: Move a BLOB Handle to a New Row
    ** METHOD: sqlite3_blob
    **
    ** ^This function is used to move an existing [BLOB handle] so that it points
    ** to a different row of the same database table. ^The new row is identified
    ** by the rowid value passed as the second argument. Only the row can be
    ** changed. ^The database, table and column on which the blob handle is open
    ** remain the same. Moving an existing [BLOB handle] to a new row is
    ** faster than closing the existing handle and opening a new one.
    **
    ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
    ** it must exist and there must be either a blob or text value stored in
    ** the nominated column.)^ ^If the new row is not present in the table, or if
    ** it does not contain a blob or text value, or if another error occurs, an
    ** SQLite error code is returned and the blob handle is considered aborted.
    ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
    ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
    ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
    ** always returns zero.
    **
    ** ^This function sets the database handle error code and message.
    */
    SQLITE_API int sqlite3_blob_reopen(sqlite3_blob*, sqlite3_int64);

    /*
    ** CAPI3REF: Close A BLOB Handle
    ** DESTRUCTOR: sqlite3_blob
    **
    ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
    ** unconditionally.  Even if this routine returns an error code, the
    ** handle is still closed.)^
    **
    ** ^If the blob handle being closed was opened for read-write access, and if
    ** the database is in auto-commit mode and there are no other open read-write
    ** blob handles or active write statements, the current transaction is
    ** committed. ^If an error occurs while committing the transaction, an error
    ** code is returned and the transaction rolled back.
    **
    ** Calling this function with an argument that is not a NULL pointer or an
    ** open blob handle results in undefined behaviour. ^Calling this routine
    ** with a null pointer (such as would be returned by a failed call to
    ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
    ** is passed a valid open blob handle, the values returned by the
    ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.
    */
    SQLITE_API int sqlite3_blob_close(sqlite3_blob*);

    /*
    ** CAPI3REF: Return The Size Of An Open BLOB
    ** METHOD: sqlite3_blob
    **
    ** ^Returns the size in bytes of the BLOB accessible via the
    ** successfully opened [BLOB handle] in its only argument.  ^The
    ** incremental blob I/O routines can only read or overwriting existing
    ** blob content; they cannot change the size of a blob.
    **
    ** This routine only works on a [BLOB handle] which has been created
    ** by a prior successful call to [sqlite3_blob_open()] and which has not
    ** been closed by [sqlite3_blob_close()].  Passing any other pointer in
    ** to this routine results in undefined and probably undesirable behavior.
    */
    SQLITE_API int sqlite3_blob_bytes(sqlite3_blob*);

    /*
    ** CAPI3REF: Read Data From A BLOB Incrementally
    ** METHOD: sqlite3_blob
    **
    ** ^(This function is used to read data from an open [BLOB handle] into a
    ** caller-supplied buffer. N bytes of data are copied into buffer Z
    ** from the open BLOB, starting at offset iOffset.)^
    **
    ** ^If offset iOffset is less than N bytes from the end of the BLOB,
    ** [SQLITE_ERROR] is returned and no data is read.  ^If N or iOffset is
    ** less than zero, [SQLITE_ERROR] is returned and no data is read.
    ** ^The size of the blob (and hence the maximum value of N+iOffset)
    ** can be determined using the [sqlite3_blob_bytes()] interface.
    **
    ** ^An attempt to read from an expired [BLOB handle] fails with an
    ** error code of [SQLITE_ABORT].
    **
    ** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
    ** Otherwise, an [error code] or an [extended error code] is returned.)^
    **
    ** This routine only works on a [BLOB handle] which has been created
    ** by a prior successful call to [sqlite3_blob_open()] and which has not
    ** been closed by [sqlite3_blob_close()].  Passing any other pointer in
    ** to this routine results in undefined and probably undesirable behavior.
    **
    ** See also: [sqlite3_blob_write()].
    */
    SQLITE_API int sqlite3_blob_read(sqlite3_blob*, void* Z, int N, int iOffset);

    /*
    ** CAPI3REF: Write Data Into A BLOB Incrementally
    ** METHOD: sqlite3_blob
    **
    ** ^(This function is used to write data into an open [BLOB handle] from a
    ** caller-supplied buffer. N bytes of data are copied from the buffer Z
    ** into the open BLOB, starting at offset iOffset.)^
    **
    ** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
    ** Otherwise, an  [error code] or an [extended error code] is returned.)^
    ** ^Unless SQLITE_MISUSE is returned, this function sets the
    ** [database connection] error code and message accessible via
    ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
    **
    ** ^If the [BLOB handle] passed as the first argument was not opened for
    ** writing (the flags parameter to [sqlite3_blob_open()] was zero),
    ** this function returns [SQLITE_READONLY].
    **
    ** This function may only modify the contents of the BLOB; it is
    ** not possible to increase the size of a BLOB using this API.
    ** ^If offset iOffset is less than N bytes from the end of the BLOB,
    ** [SQLITE_ERROR] is returned and no data is written. The size of the
    ** BLOB (and hence the maximum value of N+iOffset) can be determined
    ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less
    ** than zero [SQLITE_ERROR] is returned and no data is written.
    **
    ** ^An attempt to write to an expired [BLOB handle] fails with an
    ** error code of [SQLITE_ABORT].  ^Writes to the BLOB that occurred
    ** before the [BLOB handle] expired are not rolled back by the
    ** expiration of the handle, though of course those changes might
    ** have been overwritten by the statement that expired the BLOB handle
    ** or by other independent statements.
    **
    ** This routine only works on a [BLOB handle] which has been created
    ** by a prior successful call to [sqlite3_blob_open()] and which has not
    ** been closed by [sqlite3_blob_close()].  Passing any other pointer in
    ** to this routine results in undefined and probably undesirable behavior.
    **
    ** See also: [sqlite3_blob_read()].
    */
    SQLITE_API int sqlite3_blob_write(sqlite3_blob*, const void* z, int n, int iOffset);

    /*
    ** CAPI3REF: Virtual File System Objects
    **
    ** A virtual filesystem (VFS) is an [sqlite3_vfs] object
    ** that SQLite uses to interact
    ** with the underlying operating system.  Most SQLite builds come with a
    ** single default VFS that is appropriate for the host computer.
    ** New VFSes can be registered and existing VFSes can be unregistered.
    ** The following interfaces are provided.
    **
    ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
    ** ^Names are case sensitive.
    ** ^Names are zero-terminated UTF-8 strings.
    ** ^If there is no match, a NULL pointer is returned.
    ** ^If zVfsName is NULL then the default VFS is returned.
    **
    ** ^New VFSes are registered with sqlite3_vfs_register().
    ** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
    ** ^The same VFS can be registered multiple times without injury.
    ** ^To make an existing VFS into the default VFS, register it again
    ** with the makeDflt flag set.  If two different VFSes with the
    ** same name are registered, the behavior is undefined.  If a
    ** VFS is registered with a name that is NULL or an empty string,
    ** then the behavior is undefined.
    **
    ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
    ** ^(If the default VFS is unregistered, another VFS is chosen as
    ** the default.  The choice for the new VFS is arbitrary.)^
    */
    SQLITE_API sqlite3_vfs* sqlite3_vfs_find(const char* zVfsName);
    SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
    SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);

    /*
    ** CAPI3REF: Mutexes
    **
    ** The SQLite core uses these routines for thread
    ** synchronization. Though they are intended for internal
    ** use by SQLite, code that links against SQLite is
    ** permitted to use any of these routines.
    **
    ** The SQLite source code contains multiple implementations
    ** of these mutex routines.  An appropriate implementation
    ** is selected automatically at compile-time.  The following
    ** implementations are available in the SQLite core:
    **
    ** <ul>
    ** <li>   SQLITE_MUTEX_PTHREADS
    ** <li>   SQLITE_MUTEX_W32
    ** <li>   SQLITE_MUTEX_NOOP
    ** </ul>
    **
    ** The SQLITE_MUTEX_NOOP implementation is a set of routines
    ** that does no real locking and is appropriate for use in
    ** a single-threaded application.  The SQLITE_MUTEX_PTHREADS and
    ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
    ** and Windows.
    **
    ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
    ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
    ** implementation is included with the library. In this case the
    ** application must supply a custom mutex implementation using the
    ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
    ** before calling sqlite3_initialize() or any other public sqlite3_
    ** function that calls sqlite3_initialize().
    **
    ** ^The sqlite3_mutex_alloc() routine allocates a new
    ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()
    ** routine returns NULL if it is unable to allocate the requested
    ** mutex.  The argument to sqlite3_mutex_alloc() must one of these
    ** integer constants:
    **
    ** <ul>
    ** <li>  SQLITE_MUTEX_FAST
    ** <li>  SQLITE_MUTEX_RECURSIVE
    ** <li>  SQLITE_MUTEX_STATIC_MAIN
    ** <li>  SQLITE_MUTEX_STATIC_MEM
    ** <li>  SQLITE_MUTEX_STATIC_OPEN
    ** <li>  SQLITE_MUTEX_STATIC_PRNG
    ** <li>  SQLITE_MUTEX_STATIC_LRU
    ** <li>  SQLITE_MUTEX_STATIC_PMEM
    ** <li>  SQLITE_MUTEX_STATIC_APP1
    ** <li>  SQLITE_MUTEX_STATIC_APP2
    ** <li>  SQLITE_MUTEX_STATIC_APP3
    ** <li>  SQLITE_MUTEX_STATIC_VFS1
    ** <li>  SQLITE_MUTEX_STATIC_VFS2
    ** <li>  SQLITE_MUTEX_STATIC_VFS3
    ** </ul>
    **
    ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
    ** cause sqlite3_mutex_alloc() to create
    ** a new mutex.  ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
    ** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
    ** The mutex implementation does not need to make a distinction
    ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
    ** not want to.  SQLite will only request a recursive mutex in
    ** cases where it really needs one.  If a faster non-recursive mutex
    ** implementation is available on the host platform, the mutex subsystem
    ** might return such a mutex in response to SQLITE_MUTEX_FAST.
    **
    ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
    ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
    ** a pointer to a static preexisting mutex.  ^Nine static mutexes are
    ** used by the current version of SQLite.  Future versions of SQLite
    ** may add additional static mutexes.  Static mutexes are for internal
    ** use by SQLite only.  Applications that use SQLite mutexes should
    ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
    ** SQLITE_MUTEX_RECURSIVE.
    **
    ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
    ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
    ** returns a different mutex on every call.  ^For the static
    ** mutex types, the same mutex is returned on every call that has
    ** the same type number.
    **
    ** ^The sqlite3_mutex_free() routine deallocates a previously
    ** allocated dynamic mutex.  Attempting to deallocate a static
    ** mutex results in undefined behavior.
    **
    ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
    ** to enter a mutex.  ^If another thread is already within the mutex,
    ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
    ** SQLITE_BUSY.  ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
    ** upon successful entry.  ^(Mutexes created using
    ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
    ** In such cases, the
    ** mutex must be exited an equal number of times before another thread
    ** can enter.)^  If the same thread tries to enter any mutex other
    ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.
    **
    ** ^(Some systems (for example, Windows 95) do not support the operation
    ** implemented by sqlite3_mutex_try().  On those systems, sqlite3_mutex_try()
    ** will always return SQLITE_BUSY. The SQLite core only ever uses
    ** sqlite3_mutex_try() as an optimization so this is acceptable
    ** behavior.)^
    **
    ** ^The sqlite3_mutex_leave() routine exits a mutex that was
    ** previously entered by the same thread.   The behavior
    ** is undefined if the mutex is not currently entered by the
    ** calling thread or is not currently allocated.
    **
    ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
    ** sqlite3_mutex_leave() is a NULL pointer, then all three routines
    ** behave as no-ops.
    **
    ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
    */
    SQLITE_API sqlite3_mutex* sqlite3_mutex_alloc(int);
    SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
    SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
    SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
    SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);

    /*
    ** CAPI3REF: Mutex Methods Object
    **
    ** An instance of this structure defines the low-level routines
    ** used to allocate and use mutexes.
    **
    ** Usually, the default mutex implementations provided by SQLite are
    ** sufficient, however the application has the option of substituting a custom
    ** implementation for specialized deployments or systems for which SQLite
    ** does not provide a suitable implementation. In this case, the application
    ** creates and populates an instance of this structure to pass
    ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
    ** Additionally, an instance of this structure can be used as an
    ** output variable when querying the system for the current mutex
    ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
    **
    ** ^The xMutexInit method defined by this structure is invoked as
    ** part of system initialization by the sqlite3_initialize() function.
    ** ^The xMutexInit routine is called by SQLite exactly once for each
    ** effective call to [sqlite3_initialize()].
    **
    ** ^The xMutexEnd method defined by this structure is invoked as
    ** part of system shutdown by the sqlite3_shutdown() function. The
    ** implementation of this method is expected to release all outstanding
    ** resources obtained by the mutex methods implementation, especially
    ** those obtained by the xMutexInit method.  ^The xMutexEnd()
    ** interface is invoked exactly once for each call to [sqlite3_shutdown()].
    **
    ** ^(The remaining seven methods defined by this structure (xMutexAlloc,
    ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
    ** xMutexNotheld) implement the following interfaces (respectively):
    **
    ** <ul>
    **   <li>  [sqlite3_mutex_alloc()] </li>
    **   <li>  [sqlite3_mutex_free()] </li>
    **   <li>  [sqlite3_mutex_enter()] </li>
    **   <li>  [sqlite3_mutex_try()] </li>
    **   <li>  [sqlite3_mutex_leave()] </li>
    **   <li>  [sqlite3_mutex_held()] </li>
    **   <li>  [sqlite3_mutex_notheld()] </li>
    ** </ul>)^
    **
    ** The only difference is that the public sqlite3_XXX functions enumerated
    ** above silently ignore any invocations that pass a NULL pointer instead
    ** of a valid mutex handle. The implementations of the methods defined
    ** by this structure are not required to handle this case. The results
    ** of passing a NULL pointer instead of a valid mutex handle are undefined
    ** (i.e. it is acceptable to provide an implementation that segfaults if
    ** it is passed a NULL pointer).
    **
    ** The xMutexInit() method must be threadsafe.  It must be harmless to
    ** invoke xMutexInit() multiple times within the same process and without
    ** intervening calls to xMutexEnd().  Second and subsequent calls to
    ** xMutexInit() must be no-ops.
    **
    ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
    ** and its associates).  Similarly, xMutexAlloc() must not use SQLite memory
    ** allocation for a static mutex.  ^However xMutexAlloc() may use SQLite
    ** memory allocation for a fast or recursive mutex.
    **
    ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
    ** called, but only if the prior call to xMutexInit returned SQLITE_OK.
    ** If xMutexInit fails in any way, it is expected to clean up after itself
    ** prior to returning.
    */
    typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
    struct sqlite3_mutex_methods {
        int (*xMutexInit)(void);
        int (*xMutexEnd)(void);
        sqlite3_mutex* (*xMutexAlloc)(int);
        void (*xMutexFree)(sqlite3_mutex*);
        void (*xMutexEnter)(sqlite3_mutex*);
        int (*xMutexTry)(sqlite3_mutex*);
        void (*xMutexLeave)(sqlite3_mutex*);
        int (*xMutexHeld)(sqlite3_mutex*);
        int (*xMutexNotheld)(sqlite3_mutex*);
    };

    /*
    ** CAPI3REF: Mutex Verification Routines
    **
    ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
    ** are intended for use inside assert() statements.  The SQLite core
    ** never uses these routines except inside an assert() and applications
    ** are advised to follow the lead of the core.  The SQLite core only
    ** provides implementations for these routines when it is compiled
    ** with the SQLITE_DEBUG flag.  External mutex implementations
    ** are only required to provide these routines if SQLITE_DEBUG is
    ** defined and if NDEBUG is not defined.
    **
    ** These routines should return true if the mutex in their argument
    ** is held or not held, respectively, by the calling thread.
    **
    ** The implementation is not required to provide versions of these
    ** routines that actually work. If the implementation does not provide working
    ** versions of these routines, it should at least provide stubs that always
    ** return true so that one does not get spurious assertion failures.
    **
    ** If the argument to sqlite3_mutex_held() is a NULL pointer then
    ** the routine should return 1.   This seems counter-intuitive since
    ** clearly the mutex cannot be held if it does not exist.  But
    ** the reason the mutex does not exist is because the build is not
    ** using mutexes.  And we do not want the assert() containing the
    ** call to sqlite3_mutex_held() to fail, so a non-zero return is
    ** the appropriate thing to do.  The sqlite3_mutex_notheld()
    ** interface should also return 1 when given a NULL pointer.
    */
#ifndef NDEBUG
    SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
    SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
#endif

    /*
    ** CAPI3REF: Mutex Types
    **
    ** The [sqlite3_mutex_alloc()] interface takes a single argument
    ** which is one of these integer constants.
    **
    ** The set of static mutexes may change from one SQLite release to the
    ** next.  Applications that override the built-in mutex logic must be
    ** prepared to accommodate additional static mutexes.
    */
#define SQLITE_MUTEX_FAST             0
#define SQLITE_MUTEX_RECURSIVE        1
#define SQLITE_MUTEX_STATIC_MAIN      2
#define SQLITE_MUTEX_STATIC_MEM       3  /* sqlite3_malloc() */
#define SQLITE_MUTEX_STATIC_MEM2      4  /* NOT USED */
#define SQLITE_MUTEX_STATIC_OPEN      4  /* sqlite3BtreeOpen() */
#define SQLITE_MUTEX_STATIC_PRNG      5  /* sqlite3_randomness() */
#define SQLITE_MUTEX_STATIC_LRU       6  /* lru page list */
#define SQLITE_MUTEX_STATIC_LRU2      7  /* NOT USED */
#define SQLITE_MUTEX_STATIC_PMEM      7  /* sqlite3PageMalloc() */
#define SQLITE_MUTEX_STATIC_APP1      8  /* For use by application */
#define SQLITE_MUTEX_STATIC_APP2      9  /* For use by application */
#define SQLITE_MUTEX_STATIC_APP3     10  /* For use by application */
#define SQLITE_MUTEX_STATIC_VFS1     11  /* For use by built-in VFS */
#define SQLITE_MUTEX_STATIC_VFS2     12  /* For use by extension VFS */
#define SQLITE_MUTEX_STATIC_VFS3     13  /* For use by application VFS */

    /* Legacy compatibility: */
#define SQLITE_MUTEX_STATIC_MASTER    2


/*
** CAPI3REF: Retrieve the mutex for a database connection
** METHOD: sqlite3
**
** ^This interface returns a pointer the [sqlite3_mutex] object that
** serializes access to the [database connection] given in the argument
** when the [threading mode] is Serialized.
** ^If the [threading mode] is Single-thread or Multi-thread then this
** routine returns a NULL pointer.
*/
    SQLITE_API sqlite3_mutex* sqlite3_db_mutex(sqlite3*);

    /*
    ** CAPI3REF: Low-Level Control Of Database Files
    ** METHOD: sqlite3
    ** KEYWORDS: {file control}
    **
    ** ^The [sqlite3_file_control()] interface makes a direct call to the
    ** xFileControl method for the [sqlite3_io_methods] object associated
    ** with a particular database identified by the second argument. ^The
    ** name of the database is "main" for the main database or "temp" for the
    ** TEMP database, or the name that appears after the AS keyword for
    ** databases that are added using the [ATTACH] SQL command.
    ** ^A NULL pointer can be used in place of "main" to refer to the
    ** main database file.
    ** ^The third and fourth parameters to this routine
    ** are passed directly through to the second and third parameters of
    ** the xFileControl method.  ^The return value of the xFileControl
    ** method becomes the return value of this routine.
    **
    ** A few opcodes for [sqlite3_file_control()] are handled directly
    ** by the SQLite core and never invoke the
    ** sqlite3_io_methods.xFileControl method.
    ** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes
    ** a pointer to the underlying [sqlite3_file] object to be written into
    ** the space pointed to by the 4th parameter.  The
    ** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns
    ** the [sqlite3_file] object associated with the journal file instead of
    ** the main database.  The [SQLITE_FCNTL_VFS_POINTER] opcode returns
    ** a pointer to the underlying [sqlite3_vfs] object for the file.
    ** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter
    ** from the pager.
    **
    ** ^If the second parameter (zDbName) does not match the name of any
    ** open database file, then SQLITE_ERROR is returned.  ^This error
    ** code is not remembered and will not be recalled by [sqlite3_errcode()]
    ** or [sqlite3_errmsg()].  The underlying xFileControl method might
    ** also return SQLITE_ERROR.  There is no way to distinguish between
    ** an incorrect zDbName and an SQLITE_ERROR return from the underlying
    ** xFileControl method.
    **
    ** See also: [file control opcodes]
    */
    SQLITE_API int sqlite3_file_control(sqlite3*, const char* zDbName, int op, void*);

    /*
    ** CAPI3REF: Testing Interface
    **
    ** ^The sqlite3_test_control() interface is used to read out internal
    ** state of SQLite and to inject faults into SQLite for testing
    ** purposes.  ^The first parameter is an operation code that determines
    ** the number, meaning, and operation of all subsequent parameters.
    **
    ** This interface is not for use by applications.  It exists solely
    ** for verifying the correct operation of the SQLite library.  Depending
    ** on how the SQLite library is compiled, this interface might not exist.
    **
    ** The details of the operation codes, their meanings, the parameters
    ** they take, and what they do are all subject to change without notice.
    ** Unlike most of the SQLite API, this function is not guaranteed to
    ** operate consistently from one release to the next.
    */
    SQLITE_API int sqlite3_test_control(int op, ...);

    /*
    ** CAPI3REF: Testing Interface Operation Codes
    **
    ** These constants are the valid operation code parameters used
    ** as the first argument to [sqlite3_test_control()].
    **
    ** These parameters and their meanings are subject to change
    ** without notice.  These values are for testing purposes only.
    ** Applications should not use any of these parameters or the
    ** [sqlite3_test_control()] interface.
    */
#define SQLITE_TESTCTRL_FIRST                    5
#define SQLITE_TESTCTRL_PRNG_SAVE                5
#define SQLITE_TESTCTRL_PRNG_RESTORE             6
#define SQLITE_TESTCTRL_PRNG_RESET               7  /* NOT USED */
#define SQLITE_TESTCTRL_BITVEC_TEST              8
#define SQLITE_TESTCTRL_FAULT_INSTALL            9
#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS     10
#define SQLITE_TESTCTRL_PENDING_BYTE            11
#define SQLITE_TESTCTRL_ASSERT                  12
#define SQLITE_TESTCTRL_ALWAYS                  13
#define SQLITE_TESTCTRL_RESERVE                 14  /* NOT USED */
#define SQLITE_TESTCTRL_OPTIMIZATIONS           15
#define SQLITE_TESTCTRL_ISKEYWORD               16  /* NOT USED */
#define SQLITE_TESTCTRL_SCRATCHMALLOC           17  /* NOT USED */
#define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS      17
#define SQLITE_TESTCTRL_LOCALTIME_FAULT         18
#define SQLITE_TESTCTRL_EXPLAIN_STMT            19  /* NOT USED */
#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD    19
#define SQLITE_TESTCTRL_NEVER_CORRUPT           20
#define SQLITE_TESTCTRL_VDBE_COVERAGE           21
#define SQLITE_TESTCTRL_BYTEORDER               22
#define SQLITE_TESTCTRL_ISINIT                  23
#define SQLITE_TESTCTRL_SORTER_MMAP             24
#define SQLITE_TESTCTRL_IMPOSTER                25
#define SQLITE_TESTCTRL_PARSER_COVERAGE         26
#define SQLITE_TESTCTRL_RESULT_INTREAL          27
#define SQLITE_TESTCTRL_PRNG_SEED               28
#define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS     29
#define SQLITE_TESTCTRL_SEEK_COUNT              30
#define SQLITE_TESTCTRL_TRACEFLAGS              31
#define SQLITE_TESTCTRL_LAST                    31  /* Largest TESTCTRL */

    /*
    ** CAPI3REF: SQL Keyword Checking
    **
    ** These routines provide access to the set of SQL language keywords
    ** recognized by SQLite.  Applications can uses these routines to determine
    ** whether or not a specific identifier needs to be escaped (for example,
    ** by enclosing in double-quotes) so as not to confuse the parser.
    **
    ** The sqlite3_keyword_count() interface returns the number of distinct
    ** keywords understood by SQLite.
    **
    ** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and
    ** makes *Z point to that keyword expressed as UTF8 and writes the number
    ** of bytes in the keyword into *L.  The string that *Z points to is not
    ** zero-terminated.  The sqlite3_keyword_name(N,Z,L) routine returns
    ** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z
    ** or L are NULL or invalid pointers then calls to
    ** sqlite3_keyword_name(N,Z,L) result in undefined behavior.
    **
    ** The sqlite3_keyword_check(Z,L) interface checks to see whether or not
    ** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero
    ** if it is and zero if not.
    **
    ** The parser used by SQLite is forgiving.  It is often possible to use
    ** a keyword as an identifier as long as such use does not result in a
    ** parsing ambiguity.  For example, the statement
    ** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and
    ** creates a new table named "BEGIN" with three columns named
    ** "REPLACE", "PRAGMA", and "END".  Nevertheless, best practice is to avoid
    ** using keywords as identifiers.  Common techniques used to avoid keyword
    ** name collisions include:
    ** <ul>
    ** <li> Put all identifier names inside double-quotes.  This is the official
    **      SQL way to escape identifier names.
    ** <li> Put identifier names inside &#91;...&#93;.  This is not standard SQL,
    **      but it is what SQL Server does and so lots of programmers use this
    **      technique.
    ** <li> Begin every identifier with the letter "Z" as no SQL keywords start
    **      with "Z".
    ** <li> Include a digit somewhere in every identifier name.
    ** </ul>
    **
    ** Note that the number of keywords understood by SQLite can depend on
    ** compile-time options.  For example, "VACUUM" is not a keyword if
    ** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option.  Also,
    ** new keywords may be added to future releases of SQLite.
    */
    SQLITE_API int sqlite3_keyword_count(void);
    SQLITE_API int sqlite3_keyword_name(int, const char**, int*);
    SQLITE_API int sqlite3_keyword_check(const char*, int);

    /*
    ** CAPI3REF: Dynamic String Object
    ** KEYWORDS: {dynamic string}
    **
    ** An instance of the sqlite3_str object contains a dynamically-sized
    ** string under construction.
    **
    ** The lifecycle of an sqlite3_str object is as follows:
    ** <ol>
    ** <li> ^The sqlite3_str object is created using [sqlite3_str_new()].
    ** <li> ^Text is appended to the sqlite3_str object using various
    ** methods, such as [sqlite3_str_appendf()].
    ** <li> ^The sqlite3_str object is destroyed and the string it created
    ** is returned using the [sqlite3_str_finish()] interface.
    ** </ol>
    */
    typedef struct sqlite3_str sqlite3_str;

    /*
    ** CAPI3REF: Create A New Dynamic String Object
    ** CONSTRUCTOR: sqlite3_str
    **
    ** ^The [sqlite3_str_new(D)] interface allocates and initializes
    ** a new [sqlite3_str] object.  To avoid memory leaks, the object returned by
    ** [sqlite3_str_new()] must be freed by a subsequent call to
    ** [sqlite3_str_finish(X)].
    **
    ** ^The [sqlite3_str_new(D)] interface always returns a pointer to a
    ** valid [sqlite3_str] object, though in the event of an out-of-memory
    ** error the returned object might be a special singleton that will
    ** silently reject new text, always return SQLITE_NOMEM from
    ** [sqlite3_str_errcode()], always return 0 for
    ** [sqlite3_str_length()], and always return NULL from
    ** [sqlite3_str_finish(X)].  It is always safe to use the value
    ** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter
    ** to any of the other [sqlite3_str] methods.
    **
    ** The D parameter to [sqlite3_str_new(D)] may be NULL.  If the
    ** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum
    ** length of the string contained in the [sqlite3_str] object will be
    ** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead
    ** of [SQLITE_MAX_LENGTH].
    */
    SQLITE_API sqlite3_str* sqlite3_str_new(sqlite3*);

    /*
    ** CAPI3REF: Finalize A Dynamic String
    ** DESTRUCTOR: sqlite3_str
    **
    ** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X
    ** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()]
    ** that contains the constructed string.  The calling application should
    ** pass the returned value to [sqlite3_free()] to avoid a memory leak.
    ** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any
    ** errors were encountered during construction of the string.  ^The
    ** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the
    ** string in [sqlite3_str] object X is zero bytes long.
    */
    SQLITE_API char* sqlite3_str_finish(sqlite3_str*);

    /*
    ** CAPI3REF: Add Content To A Dynamic String
    ** METHOD: sqlite3_str
    **
    ** These interfaces add content to an sqlite3_str object previously obtained
    ** from [sqlite3_str_new()].
    **
    ** ^The [sqlite3_str_appendf(X,F,...)] and
    ** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf]
    ** functionality of SQLite to append formatted text onto the end of
    ** [sqlite3_str] object X.
    **
    ** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S
    ** onto the end of the [sqlite3_str] object X.  N must be non-negative.
    ** S must contain at least N non-zero bytes of content.  To append a
    ** zero-terminated string in its entirety, use the [sqlite3_str_appendall()]
    ** method instead.
    **
    ** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of
    ** zero-terminated string S onto the end of [sqlite3_str] object X.
    **
    ** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the
    ** single-byte character C onto the end of [sqlite3_str] object X.
    ** ^This method can be used, for example, to add whitespace indentation.
    **
    ** ^The [sqlite3_str_reset(X)] method resets the string under construction
    ** inside [sqlite3_str] object X back to zero bytes in length.
    **
    ** These methods do not return a result code.  ^If an error occurs, that fact
    ** is recorded in the [sqlite3_str] object and can be recovered by a
    ** subsequent call to [sqlite3_str_errcode(X)].
    */
    SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char* zFormat, ...);
    SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char* zFormat, va_list);
    SQLITE_API void sqlite3_str_append(sqlite3_str*, const char* zIn, int N);
    SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char* zIn);
    SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C);
    SQLITE_API void sqlite3_str_reset(sqlite3_str*);

    /*
    ** CAPI3REF: Status Of A Dynamic String
    ** METHOD: sqlite3_str
    **
    ** These interfaces return the current status of an [sqlite3_str] object.
    **
    ** ^If any prior errors have occurred while constructing the dynamic string
    ** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return
    ** an appropriate error code.  ^The [sqlite3_str_errcode(X)] method returns
    ** [SQLITE_NOMEM] following any out-of-memory error, or
    ** [SQLITE_TOOBIG] if the size of the dynamic string exceeds
    ** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors.
    **
    ** ^The [sqlite3_str_length(X)] method returns the current length, in bytes,
    ** of the dynamic string under construction in [sqlite3_str] object X.
    ** ^The length returned by [sqlite3_str_length(X)] does not include the
    ** zero-termination byte.
    **
    ** ^The [sqlite3_str_value(X)] method returns a pointer to the current
    ** content of the dynamic string under construction in X.  The value
    ** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X
    ** and might be freed or altered by any subsequent method on the same
    ** [sqlite3_str] object.  Applications must not used the pointer returned
    ** [sqlite3_str_value(X)] after any subsequent method call on the same
    ** object.  ^Applications may change the content of the string returned
    ** by [sqlite3_str_value(X)] as long as they do not write into any bytes
    ** outside the range of 0 to [sqlite3_str_length(X)] and do not read or
    ** write any byte after any subsequent sqlite3_str method call.
    */
    SQLITE_API int sqlite3_str_errcode(sqlite3_str*);
    SQLITE_API int sqlite3_str_length(sqlite3_str*);
    SQLITE_API char* sqlite3_str_value(sqlite3_str*);

    /*
    ** CAPI3REF: SQLite Runtime Status
    **
    ** ^These interfaces are used to retrieve runtime status information
    ** about the performance of SQLite, and optionally to reset various
    ** highwater marks.  ^The first argument is an integer code for
    ** the specific parameter to measure.  ^(Recognized integer codes
    ** are of the form [status parameters | SQLITE_STATUS_...].)^
    ** ^The current value of the parameter is returned into *pCurrent.
    ** ^The highest recorded value is returned in *pHighwater.  ^If the
    ** resetFlag is true, then the highest record value is reset after
    ** *pHighwater is written.  ^(Some parameters do not record the highest
    ** value.  For those parameters
    ** nothing is written into *pHighwater and the resetFlag is ignored.)^
    ** ^(Other parameters record only the highwater mark and not the current
    ** value.  For these latter parameters nothing is written into *pCurrent.)^
    **
    ** ^The sqlite3_status() and sqlite3_status64() routines return
    ** SQLITE_OK on success and a non-zero [error code] on failure.
    **
    ** If either the current value or the highwater mark is too large to
    ** be represented by a 32-bit integer, then the values returned by
    ** sqlite3_status() are undefined.
    **
    ** See also: [sqlite3_db_status()]
    */
    SQLITE_API int sqlite3_status(int op, int* pCurrent, int* pHighwater, int resetFlag);
    SQLITE_API int sqlite3_status64(
        int op,
        sqlite3_int64* pCurrent,
        sqlite3_int64* pHighwater,
        int resetFlag
    );


    /*
    ** CAPI3REF: Status Parameters
    ** KEYWORDS: {status parameters}
    **
    ** These integer constants designate various run-time status parameters
    ** that can be returned by [sqlite3_status()].
    **
    ** <dl>
    ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
    ** <dd>This parameter is the current amount of memory checked out
    ** using [sqlite3_malloc()], either directly or indirectly.  The
    ** figure includes calls made to [sqlite3_malloc()] by the application
    ** and internal memory usage by the SQLite library.  Auxiliary page-cache
    ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
    ** this parameter.  The amount returned is the sum of the allocation
    ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
    **
    ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
    ** <dd>This parameter records the largest memory allocation request
    ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
    ** internal equivalents).  Only the value returned in the
    ** *pHighwater parameter to [sqlite3_status()] is of interest.
    ** The value written into the *pCurrent parameter is undefined.</dd>)^
    **
    ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
    ** <dd>This parameter records the number of separate memory allocations
    ** currently checked out.</dd>)^
    **
    ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
    ** <dd>This parameter returns the number of pages used out of the
    ** [pagecache memory allocator] that was configured using
    ** [SQLITE_CONFIG_PAGECACHE].  The
    ** value returned is in pages, not in bytes.</dd>)^
    **
    ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
    ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
    ** <dd>This parameter returns the number of bytes of page cache
    ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
    ** buffer and where forced to overflow to [sqlite3_malloc()].  The
    ** returned value includes allocations that overflowed because they
    ** where too large (they were larger than the "sz" parameter to
    ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
    ** no space was left in the page cache.</dd>)^
    **
    ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
    ** <dd>This parameter records the largest memory allocation request
    ** handed to the [pagecache memory allocator].  Only the value returned in the
    ** *pHighwater parameter to [sqlite3_status()] is of interest.
    ** The value written into the *pCurrent parameter is undefined.</dd>)^
    **
    ** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt>
    ** <dd>No longer used.</dd>
    **
    ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
    ** <dd>No longer used.</dd>
    **
    ** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
    ** <dd>No longer used.</dd>
    **
    ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
    ** <dd>The *pHighwater parameter records the deepest parser stack.
    ** The *pCurrent value is undefined.  The *pHighwater value is only
    ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
    ** </dl>
    **
    ** New status parameters may be added from time to time.
    */
#define SQLITE_STATUS_MEMORY_USED          0
#define SQLITE_STATUS_PAGECACHE_USED       1
#define SQLITE_STATUS_PAGECACHE_OVERFLOW   2
#define SQLITE_STATUS_SCRATCH_USED         3  /* NOT USED */
#define SQLITE_STATUS_SCRATCH_OVERFLOW     4  /* NOT USED */
#define SQLITE_STATUS_MALLOC_SIZE          5
#define SQLITE_STATUS_PARSER_STACK         6
#define SQLITE_STATUS_PAGECACHE_SIZE       7
#define SQLITE_STATUS_SCRATCH_SIZE         8  /* NOT USED */
#define SQLITE_STATUS_MALLOC_COUNT         9

    /*
    ** CAPI3REF: Database Connection Status
    ** METHOD: sqlite3
    **
    ** ^This interface is used to retrieve runtime status information
    ** about a single [database connection].  ^The first argument is the
    ** database connection object to be interrogated.  ^The second argument
    ** is an integer constant, taken from the set of
    ** [SQLITE_DBSTATUS options], that
    ** determines the parameter to interrogate.  The set of
    ** [SQLITE_DBSTATUS options] is likely
    ** to grow in future releases of SQLite.
    **
    ** ^The current value of the requested parameter is written into *pCur
    ** and the highest instantaneous value is written into *pHiwtr.  ^If
    ** the resetFlg is true, then the highest instantaneous value is
    ** reset back down to the current value.
    **
    ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
    ** non-zero [error code] on failure.
    **
    ** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
    */
    SQLITE_API int sqlite3_db_status(sqlite3*, int op, int* pCur, int* pHiwtr, int resetFlg);

    /*
    ** CAPI3REF: Status Parameters for database connections
    ** KEYWORDS: {SQLITE_DBSTATUS options}
    **
    ** These constants are the available integer "verbs" that can be passed as
    ** the second argument to the [sqlite3_db_status()] interface.
    **
    ** New verbs may be added in future releases of SQLite. Existing verbs
    ** might be discontinued. Applications should check the return code from
    ** [sqlite3_db_status()] to make sure that the call worked.
    ** The [sqlite3_db_status()] interface will return a non-zero error code
    ** if a discontinued or unsupported verb is invoked.
    **
    ** <dl>
    ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
    ** <dd>This parameter returns the number of lookaside memory slots currently
    ** checked out.</dd>)^
    **
    ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
    ** <dd>This parameter returns the number of malloc attempts that were
    ** satisfied using lookaside memory. Only the high-water value is meaningful;
    ** the current value is always zero.)^
    **
    ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
    ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
    ** <dd>This parameter returns the number malloc attempts that might have
    ** been satisfied using lookaside memory but failed due to the amount of
    ** memory requested being larger than the lookaside slot size.
    ** Only the high-water value is meaningful;
    ** the current value is always zero.)^
    **
    ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
    ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
    ** <dd>This parameter returns the number malloc attempts that might have
    ** been satisfied using lookaside memory but failed due to all lookaside
    ** memory already being in use.
    ** Only the high-water value is meaningful;
    ** the current value is always zero.)^
    **
    ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
    ** <dd>This parameter returns the approximate number of bytes of heap
    ** memory used by all pager caches associated with the database connection.)^
    ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
    **
    ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]]
    ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt>
    ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a
    ** pager cache is shared between two or more connections the bytes of heap
    ** memory used by that pager cache is divided evenly between the attached
    ** connections.)^  In other words, if none of the pager caches associated
    ** with the database connection are shared, this request returns the same
    ** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are
    ** shared, the value returned by this call will be smaller than that returned
    ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with
    ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.
    **
    ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
    ** <dd>This parameter returns the approximate number of bytes of heap
    ** memory used to store the schema for all databases associated
    ** with the connection - main, temp, and any [ATTACH]-ed databases.)^
    ** ^The full amount of memory used by the schemas is reported, even if the
    ** schema memory is shared with other database connections due to
    ** [shared cache mode] being enabled.
    ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
    **
    ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
    ** <dd>This parameter returns the approximate number of bytes of heap
    ** and lookaside memory used by all prepared statements associated with
    ** the database connection.)^
    ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
    ** </dd>
    **
    ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
    ** <dd>This parameter returns the number of pager cache hits that have
    ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
    ** is always 0.
    ** </dd>
    **
    ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
    ** <dd>This parameter returns the number of pager cache misses that have
    ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
    ** is always 0.
    ** </dd>
    **
    ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
    ** <dd>This parameter returns the number of dirty cache entries that have
    ** been written to disk. Specifically, the number of pages written to the
    ** wal file in wal mode databases, or the number of pages written to the
    ** database file in rollback mode databases. Any pages written as part of
    ** transaction rollback or database recovery operations are not included.
    ** If an IO or other error occurs while writing a page to disk, the effect
    ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
    ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
    ** </dd>
    **
    ** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt>
    ** <dd>This parameter returns the number of dirty cache entries that have
    ** been written to disk in the middle of a transaction due to the page
    ** cache overflowing. Transactions are more efficient if they are written
    ** to disk all at once. When pages spill mid-transaction, that introduces
    ** additional overhead. This parameter can be used help identify
    ** inefficiencies that can be resolved by increasing the cache size.
    ** </dd>
    **
    ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
    ** <dd>This parameter returns zero for the current value if and only if
    ** all foreign key constraints (deferred or immediate) have been
    ** resolved.)^  ^The highwater mark is always 0.
    ** </dd>
    ** </dl>
    */
#define SQLITE_DBSTATUS_LOOKASIDE_USED       0
#define SQLITE_DBSTATUS_CACHE_USED           1
#define SQLITE_DBSTATUS_SCHEMA_USED          2
#define SQLITE_DBSTATUS_STMT_USED            3
#define SQLITE_DBSTATUS_LOOKASIDE_HIT        4
#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE  5
#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL  6
#define SQLITE_DBSTATUS_CACHE_HIT            7
#define SQLITE_DBSTATUS_CACHE_MISS           8
#define SQLITE_DBSTATUS_CACHE_WRITE          9
#define SQLITE_DBSTATUS_DEFERRED_FKS        10
#define SQLITE_DBSTATUS_CACHE_USED_SHARED   11
#define SQLITE_DBSTATUS_CACHE_SPILL         12
#define SQLITE_DBSTATUS_MAX                 12   /* Largest defined DBSTATUS */


    /*
    ** CAPI3REF: Prepared Statement Status
    ** METHOD: sqlite3_stmt
    **
    ** ^(Each prepared statement maintains various
    ** [SQLITE_STMTSTATUS counters] that measure the number
    ** of times it has performed specific operations.)^  These counters can
    ** be used to monitor the performance characteristics of the prepared
    ** statements.  For example, if the number of table steps greatly exceeds
    ** the number of table searches or result rows, that would tend to indicate
    ** that the prepared statement is using a full table scan rather than
    ** an index.
    **
    ** ^(This interface is used to retrieve and reset counter values from
    ** a [prepared statement].  The first argument is the prepared statement
    ** object to be interrogated.  The second argument
    ** is an integer code for a specific [SQLITE_STMTSTATUS counter]
    ** to be interrogated.)^
    ** ^The current value of the requested counter is returned.
    ** ^If the resetFlg is true, then the counter is reset to zero after this
    ** interface call returns.
    **
    ** See also: [sqlite3_status()] and [sqlite3_db_status()].
    */
    SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op, int resetFlg);

    /*
    ** CAPI3REF: Status Parameters for prepared statements
    ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
    **
    ** These preprocessor macros define integer codes that name counter
    ** values associated with the [sqlite3_stmt_status()] interface.
    ** The meanings of the various counters are as follows:
    **
    ** <dl>
    ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
    ** <dd>^This is the number of times that SQLite has stepped forward in
    ** a table as part of a full table scan.  Large numbers for this counter
    ** may indicate opportunities for performance improvement through
    ** careful use of indices.</dd>
    **
    ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
    ** <dd>^This is the number of sort operations that have occurred.
    ** A non-zero value in this counter may indicate an opportunity to
    ** improvement performance through careful use of indices.</dd>
    **
    ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
    ** <dd>^This is the number of rows inserted into transient indices that
    ** were created automatically in order to help joins run faster.
    ** A non-zero value in this counter may indicate an opportunity to
    ** improvement performance by adding permanent indices that do not
    ** need to be reinitialized each time the statement is run.</dd>
    **
    ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
    ** <dd>^This is the number of virtual machine operations executed
    ** by the prepared statement if that number is less than or equal
    ** to 2147483647.  The number of virtual machine operations can be
    ** used as a proxy for the total work done by the prepared statement.
    ** If the number of virtual machine operations exceeds 2147483647
    ** then the value returned by this statement status code is undefined.
    **
    ** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt>
    ** <dd>^This is the number of times that the prepare statement has been
    ** automatically regenerated due to schema changes or changes to
    ** [bound parameters] that might affect the query plan.
    **
    ** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt>
    ** <dd>^This is the number of times that the prepared statement has
    ** been run.  A single "run" for the purposes of this counter is one
    ** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()].
    ** The counter is incremented on the first [sqlite3_step()] call of each
    ** cycle.
    **
    ** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt>
    ** <dd>^This is the approximate number of bytes of heap memory
    ** used to store the prepared statement.  ^This value is not actually
    ** a counter, and so the resetFlg parameter to sqlite3_stmt_status()
    ** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED.
    ** </dd>
    ** </dl>
    */
#define SQLITE_STMTSTATUS_FULLSCAN_STEP     1
#define SQLITE_STMTSTATUS_SORT              2
#define SQLITE_STMTSTATUS_AUTOINDEX         3
#define SQLITE_STMTSTATUS_VM_STEP           4
#define SQLITE_STMTSTATUS_REPREPARE         5
#define SQLITE_STMTSTATUS_RUN               6
#define SQLITE_STMTSTATUS_MEMUSED           99

    /*
    ** CAPI3REF: Custom Page Cache Object
    **
    ** The sqlite3_pcache type is opaque.  It is implemented by
    ** the pluggable module.  The SQLite core has no knowledge of
    ** its size or internal structure and never deals with the
    ** sqlite3_pcache object except by holding and passing pointers
    ** to the object.
    **
    ** See [sqlite3_pcache_methods2] for additional information.
    */
    typedef struct sqlite3_pcache sqlite3_pcache;

    /*
    ** CAPI3REF: Custom Page Cache Object
    **
    ** The sqlite3_pcache_page object represents a single page in the
    ** page cache.  The page cache will allocate instances of this
    ** object.  Various methods of the page cache use pointers to instances
    ** of this object as parameters or as their return value.
    **
    ** See [sqlite3_pcache_methods2] for additional information.
    */
    typedef struct sqlite3_pcache_page sqlite3_pcache_page;
    struct sqlite3_pcache_page {
        void* pBuf;        /* The content of the page */
        void* pExtra;      /* Extra information associated with the page */
    };

    /*
    ** CAPI3REF: Application Defined Page Cache.
    ** KEYWORDS: {page cache}
    **
    ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
    ** register an alternative page cache implementation by passing in an
    ** instance of the sqlite3_pcache_methods2 structure.)^
    ** In many applications, most of the heap memory allocated by
    ** SQLite is used for the page cache.
    ** By implementing a
    ** custom page cache using this API, an application can better control
    ** the amount of memory consumed by SQLite, the way in which
    ** that memory is allocated and released, and the policies used to
    ** determine exactly which parts of a database file are cached and for
    ** how long.
    **
    ** The alternative page cache mechanism is an
    ** extreme measure that is only needed by the most demanding applications.
    ** The built-in page cache is recommended for most uses.
    **
    ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
    ** internal buffer by SQLite within the call to [sqlite3_config].  Hence
    ** the application may discard the parameter after the call to
    ** [sqlite3_config()] returns.)^
    **
    ** [[the xInit() page cache method]]
    ** ^(The xInit() method is called once for each effective
    ** call to [sqlite3_initialize()])^
    ** (usually only once during the lifetime of the process). ^(The xInit()
    ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
    ** The intent of the xInit() method is to set up global data structures
    ** required by the custom page cache implementation.
    ** ^(If the xInit() method is NULL, then the
    ** built-in default page cache is used instead of the application defined
    ** page cache.)^
    **
    ** [[the xShutdown() page cache method]]
    ** ^The xShutdown() method is called by [sqlite3_shutdown()].
    ** It can be used to clean up
    ** any outstanding resources before process shutdown, if required.
    ** ^The xShutdown() method may be NULL.
    **
    ** ^SQLite automatically serializes calls to the xInit method,
    ** so the xInit method need not be threadsafe.  ^The
    ** xShutdown method is only called from [sqlite3_shutdown()] so it does
    ** not need to be threadsafe either.  All other methods must be threadsafe
    ** in multithreaded applications.
    **
    ** ^SQLite will never invoke xInit() more than once without an intervening
    ** call to xShutdown().
    **
    ** [[the xCreate() page cache methods]]
    ** ^SQLite invokes the xCreate() method to construct a new cache instance.
    ** SQLite will typically create one cache instance for each open database file,
    ** though this is not guaranteed. ^The
    ** first parameter, szPage, is the size in bytes of the pages that must
    ** be allocated by the cache.  ^szPage will always a power of two.  ^The
    ** second parameter szExtra is a number of bytes of extra storage
    ** associated with each page cache entry.  ^The szExtra parameter will
    ** a number less than 250.  SQLite will use the
    ** extra szExtra bytes on each page to store metadata about the underlying
    ** database page on disk.  The value passed into szExtra depends
    ** on the SQLite version, the target platform, and how SQLite was compiled.
    ** ^The third argument to xCreate(), bPurgeable, is true if the cache being
    ** created will be used to cache database pages of a file stored on disk, or
    ** false if it is used for an in-memory database. The cache implementation
    ** does not have to do anything special based with the value of bPurgeable;
    ** it is purely advisory.  ^On a cache where bPurgeable is false, SQLite will
    ** never invoke xUnpin() except to deliberately delete a page.
    ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
    ** false will always have the "discard" flag set to true.
    ** ^Hence, a cache created with bPurgeable false will
    ** never contain any unpinned pages.
    **
    ** [[the xCachesize() page cache method]]
    ** ^(The xCachesize() method may be called at any time by SQLite to set the
    ** suggested maximum cache-size (number of pages stored by) the cache
    ** instance passed as the first argument. This is the value configured using
    ** the SQLite "[PRAGMA cache_size]" command.)^  As with the bPurgeable
    ** parameter, the implementation is not required to do anything with this
    ** value; it is advisory only.
    **
    ** [[the xPagecount() page cache methods]]
    ** The xPagecount() method must return the number of pages currently
    ** stored in the cache, both pinned and unpinned.
    **
    ** [[the xFetch() page cache methods]]
    ** The xFetch() method locates a page in the cache and returns a pointer to
    ** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
    ** The pBuf element of the returned sqlite3_pcache_page object will be a
    ** pointer to a buffer of szPage bytes used to store the content of a
    ** single database page.  The pExtra element of sqlite3_pcache_page will be
    ** a pointer to the szExtra bytes of extra storage that SQLite has requested
    ** for each entry in the page cache.
    **
    ** The page to be fetched is determined by the key. ^The minimum key value
    ** is 1.  After it has been retrieved using xFetch, the page is considered
    ** to be "pinned".
    **
    ** If the requested page is already in the page cache, then the page cache
    ** implementation must return a pointer to the page buffer with its content
    ** intact.  If the requested page is not already in the cache, then the
    ** cache implementation should use the value of the createFlag
    ** parameter to help it determined what action to take:
    **
    ** <table border=1 width=85% align=center>
    ** <tr><th> createFlag <th> Behavior when page is not already in cache
    ** <tr><td> 0 <td> Do not allocate a new page.  Return NULL.
    ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
    **                 Otherwise return NULL.
    ** <tr><td> 2 <td> Make every effort to allocate a new page.  Only return
    **                 NULL if allocating a new page is effectively impossible.
    ** </table>
    **
    ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1.  SQLite
    ** will only use a createFlag of 2 after a prior call with a createFlag of 1
    ** failed.)^  In between the xFetch() calls, SQLite may
    ** attempt to unpin one or more cache pages by spilling the content of
    ** pinned pages to disk and synching the operating system disk cache.
    **
    ** [[the xUnpin() page cache method]]
    ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
    ** as its second argument.  If the third parameter, discard, is non-zero,
    ** then the page must be evicted from the cache.
    ** ^If the discard parameter is
    ** zero, then the page may be discarded or retained at the discretion of
    ** page cache implementation. ^The page cache implementation
    ** may choose to evict unpinned pages at any time.
    **
    ** The cache must not perform any reference counting. A single
    ** call to xUnpin() unpins the page regardless of the number of prior calls
    ** to xFetch().
    **
    ** [[the xRekey() page cache methods]]
    ** The xRekey() method is used to change the key value associated with the
    ** page passed as the second argument. If the cache
    ** previously contains an entry associated with newKey, it must be
    ** discarded. ^Any prior cache entry associated with newKey is guaranteed not
    ** to be pinned.
    **
    ** When SQLite calls the xTruncate() method, the cache must discard all
    ** existing cache entries with page numbers (keys) greater than or equal
    ** to the value of the iLimit parameter passed to xTruncate(). If any
    ** of these pages are pinned, they are implicitly unpinned, meaning that
    ** they can be safely discarded.
    **
    ** [[the xDestroy() page cache method]]
    ** ^The xDestroy() method is used to delete a cache allocated by xCreate().
    ** All resources associated with the specified cache should be freed. ^After
    ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
    ** handle invalid, and will not use it with any other sqlite3_pcache_methods2
    ** functions.
    **
    ** [[the xShrink() page cache method]]
    ** ^SQLite invokes the xShrink() method when it wants the page cache to
    ** free up as much of heap memory as possible.  The page cache implementation
    ** is not obligated to free any memory, but well-behaved implementations should
    ** do their best.
    */
    typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
    struct sqlite3_pcache_methods2 {
        int iVersion;
        void* pArg;
        int (*xInit)(void*);
        void (*xShutdown)(void*);
        sqlite3_pcache* (*xCreate)(int szPage, int szExtra, int bPurgeable);
        void (*xCachesize)(sqlite3_pcache*, int nCachesize);
        int (*xPagecount)(sqlite3_pcache*);
        sqlite3_pcache_page* (*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
        void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
        void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
            unsigned oldKey, unsigned newKey);
        void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
        void (*xDestroy)(sqlite3_pcache*);
        void (*xShrink)(sqlite3_pcache*);
    };

    /*
    ** This is the obsolete pcache_methods object that has now been replaced
    ** by sqlite3_pcache_methods2.  This object is not used by SQLite.  It is
    ** retained in the header file for backwards compatibility only.
    */
    typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
    struct sqlite3_pcache_methods {
        void* pArg;
        int (*xInit)(void*);
        void (*xShutdown)(void*);
        sqlite3_pcache* (*xCreate)(int szPage, int bPurgeable);
        void (*xCachesize)(sqlite3_pcache*, int nCachesize);
        int (*xPagecount)(sqlite3_pcache*);
        void* (*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
        void (*xUnpin)(sqlite3_pcache*, void*, int discard);
        void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
        void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
        void (*xDestroy)(sqlite3_pcache*);
    };


    /*
    ** CAPI3REF: Online Backup Object
    **
    ** The sqlite3_backup object records state information about an ongoing
    ** online backup operation.  ^The sqlite3_backup object is created by
    ** a call to [sqlite3_backup_init()] and is destroyed by a call to
    ** [sqlite3_backup_finish()].
    **
    ** See Also: [Using the SQLite Online Backup API]
    */
    typedef struct sqlite3_backup sqlite3_backup;

    /*
    ** CAPI3REF: Online Backup API.
    **
    ** The backup API copies the content of one database into another.
    ** It is useful either for creating backups of databases or
    ** for copying in-memory databases to or from persistent files.
    **
    ** See Also: [Using the SQLite Online Backup API]
    **
    ** ^SQLite holds a write transaction open on the destination database file
    ** for the duration of the backup operation.
    ** ^The source database is read-locked only while it is being read;
    ** it is not locked continuously for the entire backup operation.
    ** ^Thus, the backup may be performed on a live source database without
    ** preventing other database connections from
    ** reading or writing to the source database while the backup is underway.
    **
    ** ^(To perform a backup operation:
    **   <ol>
    **     <li><b>sqlite3_backup_init()</b> is called once to initialize the
    **         backup,
    **     <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
    **         the data between the two databases, and finally
    **     <li><b>sqlite3_backup_finish()</b> is called to release all resources
    **         associated with the backup operation.
    **   </ol>)^
    ** There should be exactly one call to sqlite3_backup_finish() for each
    ** successful call to sqlite3_backup_init().
    **
    ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
    **
    ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
    ** [database connection] associated with the destination database
    ** and the database name, respectively.
    ** ^The database name is "main" for the main database, "temp" for the
    ** temporary database, or the name specified after the AS keyword in
    ** an [ATTACH] statement for an attached database.
    ** ^The S and M arguments passed to
    ** sqlite3_backup_init(D,N,S,M) identify the [database connection]
    ** and database name of the source database, respectively.
    ** ^The source and destination [database connections] (parameters S and D)
    ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
    ** an error.
    **
    ** ^A call to sqlite3_backup_init() will fail, returning NULL, if
    ** there is already a read or read-write transaction open on the
    ** destination database.
    **
    ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
    ** returned and an error code and error message are stored in the
    ** destination [database connection] D.
    ** ^The error code and message for the failed call to sqlite3_backup_init()
    ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
    ** [sqlite3_errmsg16()] functions.
    ** ^A successful call to sqlite3_backup_init() returns a pointer to an
    ** [sqlite3_backup] object.
    ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
    ** sqlite3_backup_finish() functions to perform the specified backup
    ** operation.
    **
    ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
    **
    ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
    ** the source and destination databases specified by [sqlite3_backup] object B.
    ** ^If N is negative, all remaining source pages are copied.
    ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
    ** are still more pages to be copied, then the function returns [SQLITE_OK].
    ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
    ** from source to destination, then it returns [SQLITE_DONE].
    ** ^If an error occurs while running sqlite3_backup_step(B,N),
    ** then an [error code] is returned. ^As well as [SQLITE_OK] and
    ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
    ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
    ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
    **
    ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
    ** <ol>
    ** <li> the destination database was opened read-only, or
    ** <li> the destination database is using write-ahead-log journaling
    ** and the destination and source page sizes differ, or
    ** <li> the destination database is an in-memory database and the
    ** destination and source page sizes differ.
    ** </ol>)^
    **
    ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
    ** the [sqlite3_busy_handler | busy-handler function]
    ** is invoked (if one is specified). ^If the
    ** busy-handler returns non-zero before the lock is available, then
    ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
    ** sqlite3_backup_step() can be retried later. ^If the source
    ** [database connection]
    ** is being used to write to the source database when sqlite3_backup_step()
    ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
    ** case the call to sqlite3_backup_step() can be retried later on. ^(If
    ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
    ** [SQLITE_READONLY] is returned, then
    ** there is no point in retrying the call to sqlite3_backup_step(). These
    ** errors are considered fatal.)^  The application must accept
    ** that the backup operation has failed and pass the backup operation handle
    ** to the sqlite3_backup_finish() to release associated resources.
    **
    ** ^The first call to sqlite3_backup_step() obtains an exclusive lock
    ** on the destination file. ^The exclusive lock is not released until either
    ** sqlite3_backup_finish() is called or the backup operation is complete
    ** and sqlite3_backup_step() returns [SQLITE_DONE].  ^Every call to
    ** sqlite3_backup_step() obtains a [shared lock] on the source database that
    ** lasts for the duration of the sqlite3_backup_step() call.
    ** ^Because the source database is not locked between calls to
    ** sqlite3_backup_step(), the source database may be modified mid-way
    ** through the backup process.  ^If the source database is modified by an
    ** external process or via a database connection other than the one being
    ** used by the backup operation, then the backup will be automatically
    ** restarted by the next call to sqlite3_backup_step(). ^If the source
    ** database is modified by the using the same database connection as is used
    ** by the backup operation, then the backup database is automatically
    ** updated at the same time.
    **
    ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
    **
    ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
    ** application wishes to abandon the backup operation, the application
    ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
    ** ^The sqlite3_backup_finish() interfaces releases all
    ** resources associated with the [sqlite3_backup] object.
    ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
    ** active write-transaction on the destination database is rolled back.
    ** The [sqlite3_backup] object is invalid
    ** and may not be used following a call to sqlite3_backup_finish().
    **
    ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
    ** sqlite3_backup_step() errors occurred, regardless or whether or not
    ** sqlite3_backup_step() completed.
    ** ^If an out-of-memory condition or IO error occurred during any prior
    ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
    ** sqlite3_backup_finish() returns the corresponding [error code].
    **
    ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
    ** is not a permanent error and does not affect the return value of
    ** sqlite3_backup_finish().
    **
    ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]
    ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
    **
    ** ^The sqlite3_backup_remaining() routine returns the number of pages still
    ** to be backed up at the conclusion of the most recent sqlite3_backup_step().
    ** ^The sqlite3_backup_pagecount() routine returns the total number of pages
    ** in the source database at the conclusion of the most recent
    ** sqlite3_backup_step().
    ** ^(The values returned by these functions are only updated by
    ** sqlite3_backup_step(). If the source database is modified in a way that
    ** changes the size of the source database or the number of pages remaining,
    ** those changes are not reflected in the output of sqlite3_backup_pagecount()
    ** and sqlite3_backup_remaining() until after the next
    ** sqlite3_backup_step().)^
    **
    ** <b>Concurrent Usage of Database Handles</b>
    **
    ** ^The source [database connection] may be used by the application for other
    ** purposes while a backup operation is underway or being initialized.
    ** ^If SQLite is compiled and configured to support threadsafe database
    ** connections, then the source database connection may be used concurrently
    ** from within other threads.
    **
    ** However, the application must guarantee that the destination
    ** [database connection] is not passed to any other API (by any thread) after
    ** sqlite3_backup_init() is called and before the corresponding call to
    ** sqlite3_backup_finish().  SQLite does not currently check to see
    ** if the application incorrectly accesses the destination [database connection]
    ** and so no error code is reported, but the operations may malfunction
    ** nevertheless.  Use of the destination database connection while a
    ** backup is in progress might also also cause a mutex deadlock.
    **
    ** If running in [shared cache mode], the application must
    ** guarantee that the shared cache used by the destination database
    ** is not accessed while the backup is running. In practice this means
    ** that the application must guarantee that the disk file being
    ** backed up to is not accessed by any connection within the process,
    ** not just the specific connection that was passed to sqlite3_backup_init().
    **
    ** The [sqlite3_backup] object itself is partially threadsafe. Multiple
    ** threads may safely make multiple concurrent calls to sqlite3_backup_step().
    ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
    ** APIs are not strictly speaking threadsafe. If they are invoked at the
    ** same time as another thread is invoking sqlite3_backup_step() it is
    ** possible that they return invalid values.
    */
    SQLITE_API sqlite3_backup* sqlite3_backup_init(
        sqlite3* pDest,                        /* Destination database handle */
        const char* zDestName,                 /* Destination database name */
        sqlite3* pSource,                      /* Source database handle */
        const char* zSourceName                /* Source database name */
    );
    SQLITE_API int sqlite3_backup_step(sqlite3_backup* p, int nPage);
    SQLITE_API int sqlite3_backup_finish(sqlite3_backup* p);
    SQLITE_API int sqlite3_backup_remaining(sqlite3_backup* p);
    SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup* p);

    /*
    ** CAPI3REF: Unlock Notification
    ** METHOD: sqlite3
    **
    ** ^When running in shared-cache mode, a database operation may fail with
    ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
    ** individual tables within the shared-cache cannot be obtained. See
    ** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
    ** ^This API may be used to register a callback that SQLite will invoke
    ** when the connection currently holding the required lock relinquishes it.
    ** ^This API is only available if the library was compiled with the
    ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
    **
    ** See Also: [Using the SQLite Unlock Notification Feature].
    **
    ** ^Shared-cache locks are released when a database connection concludes
    ** its current transaction, either by committing it or rolling it back.
    **
    ** ^When a connection (known as the blocked connection) fails to obtain a
    ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
    ** identity of the database connection (the blocking connection) that
    ** has locked the required resource is stored internally. ^After an
    ** application receives an SQLITE_LOCKED error, it may call the
    ** sqlite3_unlock_notify() method with the blocked connection handle as
    ** the first argument to register for a callback that will be invoked
    ** when the blocking connections current transaction is concluded. ^The
    ** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
    ** call that concludes the blocking connection's transaction.
    **
    ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
    ** there is a chance that the blocking connection will have already
    ** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
    ** If this happens, then the specified callback is invoked immediately,
    ** from within the call to sqlite3_unlock_notify().)^
    **
    ** ^If the blocked connection is attempting to obtain a write-lock on a
    ** shared-cache table, and more than one other connection currently holds
    ** a read-lock on the same table, then SQLite arbitrarily selects one of
    ** the other connections to use as the blocking connection.
    **
    ** ^(There may be at most one unlock-notify callback registered by a
    ** blocked connection. If sqlite3_unlock_notify() is called when the
    ** blocked connection already has a registered unlock-notify callback,
    ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
    ** called with a NULL pointer as its second argument, then any existing
    ** unlock-notify callback is canceled. ^The blocked connections
    ** unlock-notify callback may also be canceled by closing the blocked
    ** connection using [sqlite3_close()].
    **
    ** The unlock-notify callback is not reentrant. If an application invokes
    ** any sqlite3_xxx API functions from within an unlock-notify callback, a
    ** crash or deadlock may be the result.
    **
    ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
    ** returns SQLITE_OK.
    **
    ** <b>Callback Invocation Details</b>
    **
    ** When an unlock-notify callback is registered, the application provides a
    ** single void* pointer that is passed to the callback when it is invoked.
    ** However, the signature of the callback function allows SQLite to pass
    ** it an array of void* context pointers. The first argument passed to
    ** an unlock-notify callback is a pointer to an array of void* pointers,
    ** and the second is the number of entries in the array.
    **
    ** When a blocking connection's transaction is concluded, there may be
    ** more than one blocked connection that has registered for an unlock-notify
    ** callback. ^If two or more such blocked connections have specified the
    ** same callback function, then instead of invoking the callback function
    ** multiple times, it is invoked once with the set of void* context pointers
    ** specified by the blocked connections bundled together into an array.
    ** This gives the application an opportunity to prioritize any actions
    ** related to the set of unblocked database connections.
    **
    ** <b>Deadlock Detection</b>
    **
    ** Assuming that after registering for an unlock-notify callback a
    ** database waits for the callback to be issued before taking any further
    ** action (a reasonable assumption), then using this API may cause the
    ** application to deadlock. For example, if connection X is waiting for
    ** connection Y's transaction to be concluded, and similarly connection
    ** Y is waiting on connection X's transaction, then neither connection
    ** will proceed and the system may remain deadlocked indefinitely.
    **
    ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
    ** detection. ^If a given call to sqlite3_unlock_notify() would put the
    ** system in a deadlocked state, then SQLITE_LOCKED is returned and no
    ** unlock-notify callback is registered. The system is said to be in
    ** a deadlocked state if connection A has registered for an unlock-notify
    ** callback on the conclusion of connection B's transaction, and connection
    ** B has itself registered for an unlock-notify callback when connection
    ** A's transaction is concluded. ^Indirect deadlock is also detected, so
    ** the system is also considered to be deadlocked if connection B has
    ** registered for an unlock-notify callback on the conclusion of connection
    ** C's transaction, where connection C is waiting on connection A. ^Any
    ** number of levels of indirection are allowed.
    **
    ** <b>The "DROP TABLE" Exception</b>
    **
    ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
    ** always appropriate to call sqlite3_unlock_notify(). There is however,
    ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
    ** SQLite checks if there are any currently executing SELECT statements
    ** that belong to the same connection. If there are, SQLITE_LOCKED is
    ** returned. In this case there is no "blocking connection", so invoking
    ** sqlite3_unlock_notify() results in the unlock-notify callback being
    ** invoked immediately. If the application then re-attempts the "DROP TABLE"
    ** or "DROP INDEX" query, an infinite loop might be the result.
    **
    ** One way around this problem is to check the extended error code returned
    ** by an sqlite3_step() call. ^(If there is a blocking connection, then the
    ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
    ** the special "DROP TABLE/INDEX" case, the extended error code is just
    ** SQLITE_LOCKED.)^
    */
    SQLITE_API int sqlite3_unlock_notify(
        sqlite3* pBlocked,                          /* Waiting connection */
        void (*xNotify)(void** apArg, int nArg),    /* Callback function to invoke */
        void* pNotifyArg                            /* Argument to pass to xNotify */
    );


    /*
    ** CAPI3REF: String Comparison
    **
    ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
    ** and extensions to compare the contents of two buffers containing UTF-8
    ** strings in a case-independent fashion, using the same definition of "case
    ** independence" that SQLite uses internally when comparing identifiers.
    */
    SQLITE_API int sqlite3_stricmp(const char*, const char*);
    SQLITE_API int sqlite3_strnicmp(const char*, const char*, int);

    /*
    ** CAPI3REF: String Globbing
    *
    ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if
    ** string X matches the [GLOB] pattern P.
    ** ^The definition of [GLOB] pattern matching used in
    ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
    ** SQL dialect understood by SQLite.  ^The [sqlite3_strglob(P,X)] function
    ** is case sensitive.
    **
    ** Note that this routine returns zero on a match and non-zero if the strings
    ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
    **
    ** See also: [sqlite3_strlike()].
    */
    SQLITE_API int sqlite3_strglob(const char* zGlob, const char* zStr);

    /*
    ** CAPI3REF: String LIKE Matching
    *
    ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if
    ** string X matches the [LIKE] pattern P with escape character E.
    ** ^The definition of [LIKE] pattern matching used in
    ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"
    ** operator in the SQL dialect understood by SQLite.  ^For "X LIKE P" without
    ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.
    ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case
    ** insensitive - equivalent upper and lower case ASCII characters match
    ** one another.
    **
    ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though
    ** only ASCII characters are case folded.
    **
    ** Note that this routine returns zero on a match and non-zero if the strings
    ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
    **
    ** See also: [sqlite3_strglob()].
    */
    SQLITE_API int sqlite3_strlike(const char* zGlob, const char* zStr, unsigned int cEsc);

    /*
    ** CAPI3REF: Error Logging Interface
    **
    ** ^The [sqlite3_log()] interface writes a message into the [error log]
    ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
    ** ^If logging is enabled, the zFormat string and subsequent arguments are
    ** used with [sqlite3_snprintf()] to generate the final output string.
    **
    ** The sqlite3_log() interface is intended for use by extensions such as
    ** virtual tables, collating functions, and SQL functions.  While there is
    ** nothing to prevent an application from calling sqlite3_log(), doing so
    ** is considered bad form.
    **
    ** The zFormat string must not be NULL.
    **
    ** To avoid deadlocks and other threading problems, the sqlite3_log() routine
    ** will not use dynamically allocated memory.  The log message is stored in
    ** a fixed-length buffer on the stack.  If the log message is longer than
    ** a few hundred characters, it will be truncated to the length of the
    ** buffer.
    */
    SQLITE_API void sqlite3_log(int iErrCode, const char* zFormat, ...);

    /*
    ** CAPI3REF: Write-Ahead Log Commit Hook
    ** METHOD: sqlite3
    **
    ** ^The [sqlite3_wal_hook()] function is used to register a callback that
    ** is invoked each time data is committed to a database in wal mode.
    **
    ** ^(The callback is invoked by SQLite after the commit has taken place and
    ** the associated write-lock on the database released)^, so the implementation
    ** may read, write or [checkpoint] the database as required.
    **
    ** ^The first parameter passed to the callback function when it is invoked
    ** is a copy of the third parameter passed to sqlite3_wal_hook() when
    ** registering the callback. ^The second is a copy of the database handle.
    ** ^The third parameter is the name of the database that was written to -
    ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
    ** is the number of pages currently in the write-ahead log file,
    ** including those that were just committed.
    **
    ** The callback function should normally return [SQLITE_OK].  ^If an error
    ** code is returned, that error will propagate back up through the
    ** SQLite code base to cause the statement that provoked the callback
    ** to report an error, though the commit will have still occurred. If the
    ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
    ** that does not correspond to any valid SQLite error code, the results
    ** are undefined.
    **
    ** A single database handle may have at most a single write-ahead log callback
    ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
    ** previously registered write-ahead log callback. ^Note that the
    ** [sqlite3_wal_autocheckpoint()] interface and the
    ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
    ** overwrite any prior [sqlite3_wal_hook()] settings.
    */
    SQLITE_API void* sqlite3_wal_hook(
        sqlite3*,
        int(*)(void*, sqlite3*, const char*, int),
        void*
    );

    /*
    ** CAPI3REF: Configure an auto-checkpoint
    ** METHOD: sqlite3
    **
    ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
    ** [sqlite3_wal_hook()] that causes any database on [database connection] D
    ** to automatically [checkpoint]
    ** after committing a transaction if there are N or
    ** more frames in the [write-ahead log] file.  ^Passing zero or
    ** a negative value as the nFrame parameter disables automatic
    ** checkpoints entirely.
    **
    ** ^The callback registered by this function replaces any existing callback
    ** registered using [sqlite3_wal_hook()].  ^Likewise, registering a callback
    ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
    ** configured by this function.
    **
    ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
    ** from SQL.
    **
    ** ^Checkpoints initiated by this mechanism are
    ** [sqlite3_wal_checkpoint_v2|PASSIVE].
    **
    ** ^Every new [database connection] defaults to having the auto-checkpoint
    ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
    ** pages.  The use of this interface
    ** is only necessary if the default setting is found to be suboptimal
    ** for a particular application.
    */
    SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3* db, int N);

    /*
    ** CAPI3REF: Checkpoint a database
    ** METHOD: sqlite3
    **
    ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
    ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
    **
    ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the
    ** [write-ahead log] for database X on [database connection] D to be
    ** transferred into the database file and for the write-ahead log to
    ** be reset.  See the [checkpointing] documentation for addition
    ** information.
    **
    ** This interface used to be the only way to cause a checkpoint to
    ** occur.  But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]
    ** interface was added.  This interface is retained for backwards
    ** compatibility and as a convenience for applications that need to manually
    ** start a callback but which do not need the full power (and corresponding
    ** complication) of [sqlite3_wal_checkpoint_v2()].
    */
    SQLITE_API int sqlite3_wal_checkpoint(sqlite3* db, const char* zDb);

    /*
    ** CAPI3REF: Checkpoint a database
    ** METHOD: sqlite3
    **
    ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
    ** operation on database X of [database connection] D in mode M.  Status
    ** information is written back into integers pointed to by L and C.)^
    ** ^(The M parameter must be a valid [checkpoint mode]:)^
    **
    ** <dl>
    ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
    **   ^Checkpoint as many frames as possible without waiting for any database
    **   readers or writers to finish, then sync the database file if all frames
    **   in the log were checkpointed. ^The [busy-handler callback]
    **   is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.
    **   ^On the other hand, passive mode might leave the checkpoint unfinished
    **   if there are concurrent readers or writers.
    **
    ** <dt>SQLITE_CHECKPOINT_FULL<dd>
    **   ^This mode blocks (it invokes the
    **   [sqlite3_busy_handler|busy-handler callback]) until there is no
    **   database writer and all readers are reading from the most recent database
    **   snapshot. ^It then checkpoints all frames in the log file and syncs the
    **   database file. ^This mode blocks new database writers while it is pending,
    **   but new database readers are allowed to continue unimpeded.
    **
    ** <dt>SQLITE_CHECKPOINT_RESTART<dd>
    **   ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition
    **   that after checkpointing the log file it blocks (calls the
    **   [busy-handler callback])
    **   until all readers are reading from the database file only. ^This ensures
    **   that the next writer will restart the log file from the beginning.
    **   ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new
    **   database writer attempts while it is pending, but does not impede readers.
    **
    ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd>
    **   ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the
    **   addition that it also truncates the log file to zero bytes just prior
    **   to a successful return.
    ** </dl>
    **
    ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in
    ** the log file or to -1 if the checkpoint could not run because
    ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not
    ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the
    ** log file (including any that were already checkpointed before the function
    ** was called) or to -1 if the checkpoint could not run due to an error or
    ** because the database is not in WAL mode. ^Note that upon successful
    ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been
    ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.
    **
    ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If
    ** any other process is running a checkpoint operation at the same time, the
    ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a
    ** busy-handler configured, it will not be invoked in this case.
    **
    ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the
    ** exclusive "writer" lock on the database file. ^If the writer lock cannot be
    ** obtained immediately, and a busy-handler is configured, it is invoked and
    ** the writer lock retried until either the busy-handler returns 0 or the lock
    ** is successfully obtained. ^The busy-handler is also invoked while waiting for
    ** database readers as described above. ^If the busy-handler returns 0 before
    ** the writer lock is obtained or while waiting for database readers, the
    ** checkpoint operation proceeds from that point in the same way as
    ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
    ** without blocking any further. ^SQLITE_BUSY is returned in this case.
    **
    ** ^If parameter zDb is NULL or points to a zero length string, then the
    ** specified operation is attempted on all WAL databases [attached] to
    ** [database connection] db.  In this case the
    ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If
    ** an SQLITE_BUSY error is encountered when processing one or more of the
    ** attached WAL databases, the operation is still attempted on any remaining
    ** attached databases and SQLITE_BUSY is returned at the end. ^If any other
    ** error occurs while processing an attached database, processing is abandoned
    ** and the error code is returned to the caller immediately. ^If no error
    ** (SQLITE_BUSY or otherwise) is encountered while processing the attached
    ** databases, SQLITE_OK is returned.
    **
    ** ^If database zDb is the name of an attached database that is not in WAL
    ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If
    ** zDb is not NULL (or a zero length string) and is not the name of any
    ** attached database, SQLITE_ERROR is returned to the caller.
    **
    ** ^Unless it returns SQLITE_MISUSE,
    ** the sqlite3_wal_checkpoint_v2() interface
    ** sets the error information that is queried by
    ** [sqlite3_errcode()] and [sqlite3_errmsg()].
    **
    ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface
    ** from SQL.
    */
    SQLITE_API int sqlite3_wal_checkpoint_v2(
        sqlite3* db,                    /* Database handle */
        const char* zDb,                /* Name of attached database (or NULL) */
        int eMode,                      /* SQLITE_CHECKPOINT_* value */
        int* pnLog,                     /* OUT: Size of WAL log in frames */
        int* pnCkpt                     /* OUT: Total number of frames checkpointed */
    );

    /*
    ** CAPI3REF: Checkpoint Mode Values
    ** KEYWORDS: {checkpoint mode}
    **
    ** These constants define all valid values for the "checkpoint mode" passed
    ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.
    ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the
    ** meaning of each of these checkpoint modes.
    */
#define SQLITE_CHECKPOINT_PASSIVE  0  /* Do as much as possible w/o blocking */
#define SQLITE_CHECKPOINT_FULL     1  /* Wait for writers, then checkpoint */
#define SQLITE_CHECKPOINT_RESTART  2  /* Like FULL but wait for for readers */
#define SQLITE_CHECKPOINT_TRUNCATE 3  /* Like RESTART but also truncate WAL */

    /*
    ** CAPI3REF: Virtual Table Interface Configuration
    **
    ** This function may be called by either the [xConnect] or [xCreate] method
    ** of a [virtual table] implementation to configure
    ** various facets of the virtual table interface.
    **
    ** If this interface is invoked outside the context of an xConnect or
    ** xCreate virtual table method then the behavior is undefined.
    **
    ** In the call sqlite3_vtab_config(D,C,...) the D parameter is the
    ** [database connection] in which the virtual table is being created and
    ** which is passed in as the first argument to the [xConnect] or [xCreate]
    ** method that is invoking sqlite3_vtab_config().  The C parameter is one
    ** of the [virtual table configuration options].  The presence and meaning
    ** of parameters after C depend on which [virtual table configuration option]
    ** is used.
    */
    SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);

    /*
    ** CAPI3REF: Virtual Table Configuration Options
    ** KEYWORDS: {virtual table configuration options}
    ** KEYWORDS: {virtual table configuration option}
    **
    ** These macros define the various options to the
    ** [sqlite3_vtab_config()] interface that [virtual table] implementations
    ** can use to customize and optimize their behavior.
    **
    ** <dl>
    ** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]]
    ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt>
    ** <dd>Calls of the form
    ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
    ** where X is an integer.  If X is zero, then the [virtual table] whose
    ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
    ** support constraints.  In this configuration (which is the default) if
    ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
    ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
    ** specified as part of the users SQL statement, regardless of the actual
    ** ON CONFLICT mode specified.
    **
    ** If X is non-zero, then the virtual table implementation guarantees
    ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
    ** any modifications to internal or persistent data structures have been made.
    ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
    ** is able to roll back a statement or database transaction, and abandon
    ** or continue processing the current SQL statement as appropriate.
    ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
    ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
    ** had been ABORT.
    **
    ** Virtual table implementations that are required to handle OR REPLACE
    ** must do so within the [xUpdate] method. If a call to the
    ** [sqlite3_vtab_on_conflict()] function indicates that the current ON
    ** CONFLICT policy is REPLACE, the virtual table implementation should
    ** silently replace the appropriate rows within the xUpdate callback and
    ** return SQLITE_OK. Or, if this is not possible, it may return
    ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
    ** constraint handling.
    ** </dd>
    **
    ** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt>
    ** <dd>Calls of the form
    ** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the
    ** the [xConnect] or [xCreate] methods of a [virtual table] implmentation
    ** prohibits that virtual table from being used from within triggers and
    ** views.
    ** </dd>
    **
    ** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt>
    ** <dd>Calls of the form
    ** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the
    ** the [xConnect] or [xCreate] methods of a [virtual table] implmentation
    ** identify that virtual table as being safe to use from within triggers
    ** and views.  Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the
    ** virtual table can do no serious harm even if it is controlled by a
    ** malicious hacker.  Developers should avoid setting the SQLITE_VTAB_INNOCUOUS
    ** flag unless absolutely necessary.
    ** </dd>
    ** </dl>
    */
#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
#define SQLITE_VTAB_INNOCUOUS          2
#define SQLITE_VTAB_DIRECTONLY         3

    /*
    ** CAPI3REF: Determine The Virtual Table Conflict Policy
    **
    ** This function may only be called from within a call to the [xUpdate] method
    ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
    ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
    ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
    ** of the SQL statement that triggered the call to the [xUpdate] method of the
    ** [virtual table].
    */
    SQLITE_API int sqlite3_vtab_on_conflict(sqlite3*);

    /*
    ** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE
    **
    ** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn]
    ** method of a [virtual table], then it might return true if the
    ** column is being fetched as part of an UPDATE operation during which the
    ** column value will not change.  The virtual table implementation can use
    ** this hint as permission to substitute a return value that is less
    ** expensive to compute and that the corresponding
    ** [xUpdate] method understands as a "no-change" value.
    **
    ** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that
    ** the column is not changed by the UPDATE statement, then the xColumn
    ** method can optionally return without setting a result, without calling
    ** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces].
    ** In that case, [sqlite3_value_nochange(X)] will return true for the
    ** same column in the [xUpdate] method.
    **
    ** The sqlite3_vtab_nochange() routine is an optimization.  Virtual table
    ** implementations should continue to give a correct answer even if the
    ** sqlite3_vtab_nochange() interface were to always return false.  In the
    ** current implementation, the sqlite3_vtab_nochange() interface does always
    ** returns false for the enhanced [UPDATE FROM] statement.
    */
    SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*);

    /*
    ** CAPI3REF: Determine The Collation For a Virtual Table Constraint
    **
    ** This function may only be called from within a call to the [xBestIndex]
    ** method of a [virtual table].
    **
    ** The first argument must be the sqlite3_index_info object that is the
    ** first parameter to the xBestIndex() method. The second argument must be
    ** an index into the aConstraint[] array belonging to the sqlite3_index_info
    ** structure passed to xBestIndex. This function returns a pointer to a buffer
    ** containing the name of the collation sequence for the corresponding
    ** constraint.
    */
    SQLITE_API SQLITE_EXPERIMENTAL const char* sqlite3_vtab_collation(sqlite3_index_info*, int);

    /*
    ** CAPI3REF: Conflict resolution modes
    ** KEYWORDS: {conflict resolution mode}
    **
    ** These constants are returned by [sqlite3_vtab_on_conflict()] to
    ** inform a [virtual table] implementation what the [ON CONFLICT] mode
    ** is for the SQL statement being evaluated.
    **
    ** Note that the [SQLITE_IGNORE] constant is also used as a potential
    ** return value from the [sqlite3_set_authorizer()] callback and that
    ** [SQLITE_ABORT] is also a [result code].
    */
#define SQLITE_ROLLBACK 1
    /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
#define SQLITE_FAIL     3
/* #define SQLITE_ABORT 4  // Also an error code */
#define SQLITE_REPLACE  5

/*
** CAPI3REF: Prepared Statement Scan Status Opcodes
** KEYWORDS: {scanstatus options}
**
** The following constants can be used for the T parameter to the
** [sqlite3_stmt_scanstatus(S,X,T,V)] interface.  Each constant designates a
** different metric for sqlite3_stmt_scanstatus() to return.
**
** When the value returned to V is a string, space to hold that string is
** managed by the prepared statement S and will be automatically freed when
** S is finalized.
**
** <dl>
** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>
** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be
** set to the total number of times that the X-th loop has run.</dd>
**
** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>
** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set
** to the total number of rows examined by all iterations of the X-th loop.</dd>
**
** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>
** <dd>^The "double" variable pointed to by the V parameter will be set to the
** query planner's estimate for the average number of rows output from each
** iteration of the X-th loop.  If the query planner's estimates was accurate,
** then this value will approximate the quotient NVISIT/NLOOP and the
** product of this value for all prior loops with the same SELECTID will
** be the NLOOP value for the current loop.
**
** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
** <dd>^The "const char *" variable pointed to by the V parameter will be set
** to a zero-terminated UTF-8 string containing the name of the index or table
** used for the X-th loop.
**
** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>
** <dd>^The "const char *" variable pointed to by the V parameter will be set
** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]
** description for the X-th loop.
**
** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt>
** <dd>^The "int" variable pointed to by the V parameter will be set to the
** "select-id" for the X-th loop.  The select-id identifies which query or
** subquery the loop is part of.  The main query has a select-id of zero.
** The select-id is the same value as is output in the first column
** of an [EXPLAIN QUERY PLAN] query.
** </dl>
*/
#define SQLITE_SCANSTAT_NLOOP    0
#define SQLITE_SCANSTAT_NVISIT   1
#define SQLITE_SCANSTAT_EST      2
#define SQLITE_SCANSTAT_NAME     3
#define SQLITE_SCANSTAT_EXPLAIN  4
#define SQLITE_SCANSTAT_SELECTID 5

/*
** CAPI3REF: Prepared Statement Scan Status
** METHOD: sqlite3_stmt
**
** This interface returns information about the predicted and measured
** performance for pStmt.  Advanced applications can use this
** interface to compare the predicted and the measured performance and
** issue warnings and/or rerun [ANALYZE] if discrepancies are found.
**
** Since this interface is expected to be rarely used, it is only
** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS]
** compile-time option.
**
** The "iScanStatusOp" parameter determines which status information to return.
** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior
** of this interface is undefined.
** ^The requested measurement is written into a variable pointed to by
** the "pOut" parameter.
** Parameter "idx" identifies the specific loop to retrieve statistics for.
** Loops are numbered starting from zero. ^If idx is out of range - less than
** zero or greater than or equal to the total number of loops used to implement
** the statement - a non-zero value is returned and the variable that pOut
** points to is unchanged.
**
** ^Statistics might not be available for all loops in all statements. ^In cases
** where there exist loops with no available statistics, this function behaves
** as if the loop did not exist - it returns non-zero and leave the variable
** that pOut points to unchanged.
**
** See also: [sqlite3_stmt_scanstatus_reset()]
*/
    SQLITE_API int sqlite3_stmt_scanstatus(
        sqlite3_stmt* pStmt,      /* Prepared statement for which info desired */
        int idx,                  /* Index of loop to report on */
        int iScanStatusOp,        /* Information desired.  SQLITE_SCANSTAT_* */
        void* pOut                /* Result written here */
    );

    /*
    ** CAPI3REF: Zero Scan-Status Counters
    ** METHOD: sqlite3_stmt
    **
    ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
    **
    ** This API is only available if the library is built with pre-processor
    ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
    */
    SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);

    /*
    ** CAPI3REF: Flush caches to disk mid-transaction
    ** METHOD: sqlite3
    **
    ** ^If a write-transaction is open on [database connection] D when the
    ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty
    ** pages in the pager-cache that are not currently in use are written out
    ** to disk. A dirty page may be in use if a database cursor created by an
    ** active SQL statement is reading from it, or if it is page 1 of a database
    ** file (page 1 is always "in use").  ^The [sqlite3_db_cacheflush(D)]
    ** interface flushes caches for all schemas - "main", "temp", and
    ** any [attached] databases.
    **
    ** ^If this function needs to obtain extra database locks before dirty pages
    ** can be flushed to disk, it does so. ^If those locks cannot be obtained
    ** immediately and there is a busy-handler callback configured, it is invoked
    ** in the usual manner. ^If the required lock still cannot be obtained, then
    ** the database is skipped and an attempt made to flush any dirty pages
    ** belonging to the next (if any) database. ^If any databases are skipped
    ** because locks cannot be obtained, but no other error occurs, this
    ** function returns SQLITE_BUSY.
    **
    ** ^If any other error occurs while flushing dirty pages to disk (for
    ** example an IO error or out-of-memory condition), then processing is
    ** abandoned and an SQLite [error code] is returned to the caller immediately.
    **
    ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK.
    **
    ** ^This function does not set the database handle error code or message
    ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions.
    */
    SQLITE_API int sqlite3_db_cacheflush(sqlite3*);

    /*
    ** CAPI3REF: The pre-update hook.
    ** METHOD: sqlite3
    **
    ** ^These interfaces are only available if SQLite is compiled using the
    ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option.
    **
    ** ^The [sqlite3_preupdate_hook()] interface registers a callback function
    ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation
    ** on a database table.
    ** ^At most one preupdate hook may be registered at a time on a single
    ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides
    ** the previous setting.
    ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]
    ** with a NULL pointer as the second parameter.
    ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as
    ** the first parameter to callbacks.
    **
    ** ^The preupdate hook only fires for changes to real database tables; the
    ** preupdate hook is not invoked for changes to [virtual tables] or to
    ** system tables like sqlite_sequence or sqlite_stat1.
    **
    ** ^The second parameter to the preupdate callback is a pointer to
    ** the [database connection] that registered the preupdate hook.
    ** ^The third parameter to the preupdate callback is one of the constants
    ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the
    ** kind of update operation that is about to occur.
    ** ^(The fourth parameter to the preupdate callback is the name of the
    ** database within the database connection that is being modified.  This
    ** will be "main" for the main database or "temp" for TEMP tables or
    ** the name given after the AS keyword in the [ATTACH] statement for attached
    ** databases.)^
    ** ^The fifth parameter to the preupdate callback is the name of the
    ** table that is being modified.
    **
    ** For an UPDATE or DELETE operation on a [rowid table], the sixth
    ** parameter passed to the preupdate callback is the initial [rowid] of the
    ** row being modified or deleted. For an INSERT operation on a rowid table,
    ** or any operation on a WITHOUT ROWID table, the value of the sixth
    ** parameter is undefined. For an INSERT or UPDATE on a rowid table the
    ** seventh parameter is the final rowid value of the row being inserted
    ** or updated. The value of the seventh parameter passed to the callback
    ** function is not defined for operations on WITHOUT ROWID tables, or for
    ** DELETE operations on rowid tables.
    **
    ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],
    ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces
    ** provide additional information about a preupdate event. These routines
    ** may only be called from within a preupdate callback.  Invoking any of
    ** these routines from outside of a preupdate callback or with a
    ** [database connection] pointer that is different from the one supplied
    ** to the preupdate callback results in undefined and probably undesirable
    ** behavior.
    **
    ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns
    ** in the row that is being inserted, updated, or deleted.
    **
    ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to
    ** a [protected sqlite3_value] that contains the value of the Nth column of
    ** the table row before it is updated.  The N parameter must be between 0
    ** and one less than the number of columns or the behavior will be
    ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE
    ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the
    ** behavior is undefined.  The [sqlite3_value] that P points to
    ** will be destroyed when the preupdate callback returns.
    **
    ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to
    ** a [protected sqlite3_value] that contains the value of the Nth column of
    ** the table row after it is updated.  The N parameter must be between 0
    ** and one less than the number of columns or the behavior will be
    ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE
    ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the
    ** behavior is undefined.  The [sqlite3_value] that P points to
    ** will be destroyed when the preupdate callback returns.
    **
    ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate
    ** callback was invoked as a result of a direct insert, update, or delete
    ** operation; or 1 for inserts, updates, or deletes invoked by top-level
    ** triggers; or 2 for changes resulting from triggers called by top-level
    ** triggers; and so forth.
    **
    ** See also:  [sqlite3_update_hook()]
    */
#if defined(SQLITE_ENABLE_PREUPDATE_HOOK)
    SQLITE_API void* sqlite3_preupdate_hook(
        sqlite3* db,
        void(*xPreUpdate)(
            void* pCtx,                   /* Copy of third arg to preupdate_hook() */
            sqlite3* db,                  /* Database handle */
            int op,                       /* SQLITE_UPDATE, DELETE or INSERT */
            char const* zDb,              /* Database name */
            char const* zName,            /* Table name */
            sqlite3_int64 iKey1,          /* Rowid of row about to be deleted/updated */
            sqlite3_int64 iKey2           /* New rowid value (for a rowid UPDATE) */
            ),
        void*
    );
    SQLITE_API int sqlite3_preupdate_old(sqlite3*, int, sqlite3_value**);
    SQLITE_API int sqlite3_preupdate_count(sqlite3*);
    SQLITE_API int sqlite3_preupdate_depth(sqlite3*);
    SQLITE_API int sqlite3_preupdate_new(sqlite3*, int, sqlite3_value**);
#endif

    /*
    ** CAPI3REF: Low-level system error code
    ** METHOD: sqlite3
    **
    ** ^Attempt to return the underlying operating system error code or error
    ** number that caused the most recent I/O error or failure to open a file.
    ** The return value is OS-dependent.  For example, on unix systems, after
    ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be
    ** called to get back the underlying "errno" that caused the problem, such
    ** as ENOSPC, EAUTH, EISDIR, and so forth.
    */
    SQLITE_API int sqlite3_system_errno(sqlite3*);

    /*
    ** CAPI3REF: Database Snapshot
    ** KEYWORDS: {snapshot} {sqlite3_snapshot}
    **
    ** An instance of the snapshot object records the state of a [WAL mode]
    ** database for some specific point in history.
    **
    ** In [WAL mode], multiple [database connections] that are open on the
    ** same database file can each be reading a different historical version
    ** of the database file.  When a [database connection] begins a read
    ** transaction, that connection sees an unchanging copy of the database
    ** as it existed for the point in time when the transaction first started.
    ** Subsequent changes to the database from other connections are not seen
    ** by the reader until a new read transaction is started.
    **
    ** The sqlite3_snapshot object records state information about an historical
    ** version of the database file so that it is possible to later open a new read
    ** transaction that sees that historical version of the database rather than
    ** the most recent version.
    */
    typedef struct sqlite3_snapshot {
        unsigned char hidden[48];
    } sqlite3_snapshot;

    /*
    ** CAPI3REF: Record A Database Snapshot
    ** CONSTRUCTOR: sqlite3_snapshot
    **
    ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a
    ** new [sqlite3_snapshot] object that records the current state of
    ** schema S in database connection D.  ^On success, the
    ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly
    ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK.
    ** If there is not already a read-transaction open on schema S when
    ** this function is called, one is opened automatically.
    **
    ** The following must be true for this function to succeed. If any of
    ** the following statements are false when sqlite3_snapshot_get() is
    ** called, SQLITE_ERROR is returned. The final value of *P is undefined
    ** in this case.
    **
    ** <ul>
    **   <li> The database handle must not be in [autocommit mode].
    **
    **   <li> Schema S of [database connection] D must be a [WAL mode] database.
    **
    **   <li> There must not be a write transaction open on schema S of database
    **        connection D.
    **
    **   <li> One or more transactions must have been written to the current wal
    **        file since it was created on disk (by any connection). This means
    **        that a snapshot cannot be taken on a wal mode database with no wal
    **        file immediately after it is first opened. At least one transaction
    **        must be written to it first.
    ** </ul>
    **
    ** This function may also return SQLITE_NOMEM.  If it is called with the
    ** database handle in autocommit mode but fails for some other reason,
    ** whether or not a read transaction is opened on schema S is undefined.
    **
    ** The [sqlite3_snapshot] object returned from a successful call to
    ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()]
    ** to avoid a memory leak.
    **
    ** The [sqlite3_snapshot_get()] interface is only available when the
    ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
    */
    SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get(
        sqlite3* db,
        const char* zSchema,
        sqlite3_snapshot** ppSnapshot
    );

    /*
    ** CAPI3REF: Start a read transaction on an historical snapshot
    ** METHOD: sqlite3_snapshot
    **
    ** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read
    ** transaction or upgrades an existing one for schema S of
    ** [database connection] D such that the read transaction refers to
    ** historical [snapshot] P, rather than the most recent change to the
    ** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK
    ** on success or an appropriate [error code] if it fails.
    **
    ** ^In order to succeed, the database connection must not be in
    ** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there
    ** is already a read transaction open on schema S, then the database handle
    ** must have no active statements (SELECT statements that have been passed
    ** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()).
    ** SQLITE_ERROR is returned if either of these conditions is violated, or
    ** if schema S does not exist, or if the snapshot object is invalid.
    **
    ** ^A call to sqlite3_snapshot_open() will fail to open if the specified
    ** snapshot has been overwritten by a [checkpoint]. In this case
    ** SQLITE_ERROR_SNAPSHOT is returned.
    **
    ** If there is already a read transaction open when this function is
    ** invoked, then the same read transaction remains open (on the same
    ** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT
    ** is returned. If another error code - for example SQLITE_PROTOCOL or an
    ** SQLITE_IOERR error code - is returned, then the final state of the
    ** read transaction is undefined. If SQLITE_OK is returned, then the
    ** read transaction is now open on database snapshot P.
    **
    ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the
    ** database connection D does not know that the database file for
    ** schema S is in [WAL mode].  A database connection might not know
    ** that the database file is in [WAL mode] if there has been no prior
    ** I/O on that database connection, or if the database entered [WAL mode]
    ** after the most recent I/O on the database connection.)^
    ** (Hint: Run "[PRAGMA application_id]" against a newly opened
    ** database connection in order to make it ready to use snapshots.)
    **
    ** The [sqlite3_snapshot_open()] interface is only available when the
    ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
    */
    SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open(
        sqlite3* db,
        const char* zSchema,
        sqlite3_snapshot* pSnapshot
    );

    /*
    ** CAPI3REF: Destroy a snapshot
    ** DESTRUCTOR: sqlite3_snapshot
    **
    ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.
    ** The application must eventually free every [sqlite3_snapshot] object
    ** using this routine to avoid a memory leak.
    **
    ** The [sqlite3_snapshot_free()] interface is only available when the
    ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
    */
    SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*);

    /*
    ** CAPI3REF: Compare the ages of two snapshot handles.
    ** METHOD: sqlite3_snapshot
    **
    ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages
    ** of two valid snapshot handles.
    **
    ** If the two snapshot handles are not associated with the same database
    ** file, the result of the comparison is undefined.
    **
    ** Additionally, the result of the comparison is only valid if both of the
    ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the
    ** last time the wal file was deleted. The wal file is deleted when the
    ** database is changed back to rollback mode or when the number of database
    ** clients drops to zero. If either snapshot handle was obtained before the
    ** wal file was last deleted, the value returned by this function
    ** is undefined.
    **
    ** Otherwise, this API returns a negative value if P1 refers to an older
    ** snapshot than P2, zero if the two handles refer to the same database
    ** snapshot, and a positive value if P1 is a newer snapshot than P2.
    **
    ** This interface is only available if SQLite is compiled with the
    ** [SQLITE_ENABLE_SNAPSHOT] option.
    */
    SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp(
        sqlite3_snapshot* p1,
        sqlite3_snapshot* p2
    );

    /*
    ** CAPI3REF: Recover snapshots from a wal file
    ** METHOD: sqlite3_snapshot
    **
    ** If a [WAL file] remains on disk after all database connections close
    ** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control]
    ** or because the last process to have the database opened exited without
    ** calling [sqlite3_close()]) and a new connection is subsequently opened
    ** on that database and [WAL file], the [sqlite3_snapshot_open()] interface
    ** will only be able to open the last transaction added to the WAL file
    ** even though the WAL file contains other valid transactions.
    **
    ** This function attempts to scan the WAL file associated with database zDb
    ** of database handle db and make all valid snapshots available to
    ** sqlite3_snapshot_open(). It is an error if there is already a read
    ** transaction open on the database, or if the database is not a WAL mode
    ** database.
    **
    ** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
    **
    ** This interface is only available if SQLite is compiled with the
    ** [SQLITE_ENABLE_SNAPSHOT] option.
    */
    SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3* db, const char* zDb);

    /*
    ** CAPI3REF: Serialize a database
    **
    ** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory
    ** that is a serialization of the S database on [database connection] D.
    ** If P is not a NULL pointer, then the size of the database in bytes
    ** is written into *P.
    **
    ** For an ordinary on-disk database file, the serialization is just a
    ** copy of the disk file.  For an in-memory database or a "TEMP" database,
    ** the serialization is the same sequence of bytes which would be written
    ** to disk if that database where backed up to disk.
    **
    ** The usual case is that sqlite3_serialize() copies the serialization of
    ** the database into memory obtained from [sqlite3_malloc64()] and returns
    ** a pointer to that memory.  The caller is responsible for freeing the
    ** returned value to avoid a memory leak.  However, if the F argument
    ** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations
    ** are made, and the sqlite3_serialize() function will return a pointer
    ** to the contiguous memory representation of the database that SQLite
    ** is currently using for that database, or NULL if the no such contiguous
    ** memory representation of the database exists.  A contiguous memory
    ** representation of the database will usually only exist if there has
    ** been a prior call to [sqlite3_deserialize(D,S,...)] with the same
    ** values of D and S.
    ** The size of the database is written into *P even if the
    ** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy
    ** of the database exists.
    **
    ** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the
    ** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory
    ** allocation error occurs.
    **
    ** This interface is only available if SQLite is compiled with the
    ** [SQLITE_ENABLE_DESERIALIZE] option.
    */
    SQLITE_API unsigned char* sqlite3_serialize(
        sqlite3* db,           /* The database connection */
        const char* zSchema,   /* Which DB to serialize. ex: "main", "temp", ... */
        sqlite3_int64* piSize, /* Write size of the DB here, if not NULL */
        unsigned int mFlags    /* Zero or more SQLITE_SERIALIZE_* flags */
    );

    /*
    ** CAPI3REF: Flags for sqlite3_serialize
    **
    ** Zero or more of the following constants can be OR-ed together for
    ** the F argument to [sqlite3_serialize(D,S,P,F)].
    **
    ** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return
    ** a pointer to contiguous in-memory database that it is currently using,
    ** without making a copy of the database.  If SQLite is not currently using
    ** a contiguous in-memory database, then this option causes
    ** [sqlite3_serialize()] to return a NULL pointer.  SQLite will only be
    ** using a contiguous in-memory database if it has been initialized by a
    ** prior call to [sqlite3_deserialize()].
    */
#define SQLITE_SERIALIZE_NOCOPY 0x001   /* Do no memory allocations */

    /*
    ** CAPI3REF: Deserialize a database
    **
    ** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the
    ** [database connection] D to disconnect from database S and then
    ** reopen S as an in-memory database based on the serialization contained
    ** in P.  The serialized database P is N bytes in size.  M is the size of
    ** the buffer P, which might be larger than N.  If M is larger than N, and
    ** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is
    ** permitted to add content to the in-memory database as long as the total
    ** size does not exceed M bytes.
    **
    ** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will
    ** invoke sqlite3_free() on the serialization buffer when the database
    ** connection closes.  If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then
    ** SQLite will try to increase the buffer size using sqlite3_realloc64()
    ** if writes on the database cause it to grow larger than M bytes.
    **
    ** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the
    ** database is currently in a read transaction or is involved in a backup
    ** operation.
    **
    ** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the
    ** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then
    ** [sqlite3_free()] is invoked on argument P prior to returning.
    **
    ** This interface is only available if SQLite is compiled with the
    ** [SQLITE_ENABLE_DESERIALIZE] option.
    */
    SQLITE_API int sqlite3_deserialize(
        sqlite3* db,            /* The database connection */
        const char* zSchema,    /* Which DB to reopen with the deserialization */
        unsigned char* pData,   /* The serialized database content */
        sqlite3_int64 szDb,     /* Number bytes in the deserialization */
        sqlite3_int64 szBuf,    /* Total size of buffer pData[] */
        unsigned mFlags         /* Zero or more SQLITE_DESERIALIZE_* flags */
    );

    /*
    ** CAPI3REF: Flags for sqlite3_deserialize()
    **
    ** The following are allowed values for 6th argument (the F argument) to
    ** the [sqlite3_deserialize(D,S,P,N,M,F)] interface.
    **
    ** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization
    ** in the P argument is held in memory obtained from [sqlite3_malloc64()]
    ** and that SQLite should take ownership of this memory and automatically
    ** free it when it has finished using it.  Without this flag, the caller
    ** is responsible for freeing any dynamically allocated memory.
    **
    ** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to
    ** grow the size of the database using calls to [sqlite3_realloc64()].  This
    ** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used.
    ** Without this flag, the deserialized database cannot increase in size beyond
    ** the number of bytes specified by the M parameter.
    **
    ** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database
    ** should be treated as read-only.
    */
#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */
#define SQLITE_DESERIALIZE_RESIZEABLE  2 /* Resize using sqlite3_realloc64() */
#define SQLITE_DESERIALIZE_READONLY    4 /* Database is read-only */

    /*
    ** Undo the hack that converts floating point types to integer for
    ** builds on processors without floating point support.
    */
#ifdef SQLITE_OMIT_FLOATING_POINT
# undef double
#endif

#ifdef __cplusplus
}  /* End of the 'extern "C"' block */
#endif
#endif /* SQLITE3_H */

/******** Begin file sqlite3rtree.h *********/
/*
** 2010 August 30
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
*/

#ifndef _SQLITE3RTREE_H_
#define _SQLITE3RTREE_H_


#ifdef __cplusplus
extern "C" {
#endif

    typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
    typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;

    /* The double-precision datatype used by RTree depends on the
    ** SQLITE_RTREE_INT_ONLY compile-time option.
    */
#ifdef SQLITE_RTREE_INT_ONLY
    typedef sqlite3_int64 sqlite3_rtree_dbl;
#else
    typedef double sqlite3_rtree_dbl;
#endif

    /*
    ** Register a geometry callback named zGeom that can be used as part of an
    ** R-Tree geometry query as follows:
    **
    **   SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
    */
    SQLITE_API int sqlite3_rtree_geometry_callback(
        sqlite3* db,
        const char* zGeom,
        int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*, int*),
        void* pContext
    );


    /*
    ** A pointer to a structure of the following type is passed as the first
    ** argument to callbacks registered using rtree_geometry_callback().
    */
    struct sqlite3_rtree_geometry {
        void* pContext;                 /* Copy of pContext passed to s_r_g_c() */
        int nParam;                     /* Size of array aParam[] */
        sqlite3_rtree_dbl* aParam;      /* Parameters passed to SQL geom function */
        void* pUser;                    /* Callback implementation user data */
        void (*xDelUser)(void*);       /* Called by SQLite to clean up pUser */
    };

    /*
    ** Register a 2nd-generation geometry callback named zScore that can be
    ** used as part of an R-Tree geometry query as follows:
    **
    **   SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
    */
    SQLITE_API int sqlite3_rtree_query_callback(
        sqlite3* db,
        const char* zQueryFunc,
        int (*xQueryFunc)(sqlite3_rtree_query_info*),
        void* pContext,
        void (*xDestructor)(void*)
    );


    /*
    ** A pointer to a structure of the following type is passed as the
    ** argument to scored geometry callback registered using
    ** sqlite3_rtree_query_callback().
    **
    ** Note that the first 5 fields of this structure are identical to
    ** sqlite3_rtree_geometry.  This structure is a subclass of
    ** sqlite3_rtree_geometry.
    */
    struct sqlite3_rtree_query_info {
        void* pContext;                   /* pContext from when function registered */
        int nParam;                       /* Number of function parameters */
        sqlite3_rtree_dbl* aParam;        /* value of function parameters */
        void* pUser;                      /* callback can use this, if desired */
        void (*xDelUser)(void*);          /* function to free pUser */
        sqlite3_rtree_dbl* aCoord;        /* Coordinates of node or entry to check */
        unsigned int* anQueue;            /* Number of pending entries in the queue */
        int nCoord;                       /* Number of coordinates */
        int iLevel;                       /* Level of current node or entry */
        int mxLevel;                      /* The largest iLevel value in the tree */
        sqlite3_int64 iRowid;             /* Rowid for current entry */
        sqlite3_rtree_dbl rParentScore;   /* Score of parent node */
        int eParentWithin;                /* Visibility of parent node */
        int eWithin;                      /* OUT: Visibility */
        sqlite3_rtree_dbl rScore;         /* OUT: Write the score here */
        /* The following fields are only available in 3.8.11 and later */
        sqlite3_value** apSqlParam;       /* Original SQL values of parameters */
    };

    /*
    ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
    */
#define NOT_WITHIN       0   /* Object completely outside of query region */
#define PARTLY_WITHIN    1   /* Object partially overlaps query region */
#define FULLY_WITHIN     2   /* Object fully contained within query region */


#ifdef __cplusplus
}  /* end of the 'extern "C"' block */
#endif

#endif  /* ifndef _SQLITE3RTREE_H_ */

/******** End of sqlite3rtree.h *********/
/******** Begin file sqlite3session.h *********/

#if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION)
#define __SQLITESESSION_H_ 1

/*
** Make sure we can call this stuff from C++.
*/
#ifdef __cplusplus
extern "C" {
#endif


    /*
    ** CAPI3REF: Session Object Handle
    **
    ** An instance of this object is a [session] that can be used to
    ** record changes to a database.
    */
    typedef struct sqlite3_session sqlite3_session;

    /*
    ** CAPI3REF: Changeset Iterator Handle
    **
    ** An instance of this object acts as a cursor for iterating
    ** over the elements of a [changeset] or [patchset].
    */
    typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;

    /*
    ** CAPI3REF: Create A New Session Object
    ** CONSTRUCTOR: sqlite3_session
    **
    ** Create a new session object attached to database handle db. If successful,
    ** a pointer to the new object is written to *ppSession and SQLITE_OK is
    ** returned. If an error occurs, *ppSession is set to NULL and an SQLite
    ** error code (e.g. SQLITE_NOMEM) is returned.
    **
    ** It is possible to create multiple session objects attached to a single
    ** database handle.
    **
    ** Session objects created using this function should be deleted using the
    ** [sqlite3session_delete()] function before the database handle that they
    ** are attached to is itself closed. If the database handle is closed before
    ** the session object is deleted, then the results of calling any session
    ** module function, including [sqlite3session_delete()] on the session object
    ** are undefined.
    **
    ** Because the session module uses the [sqlite3_preupdate_hook()] API, it
    ** is not possible for an application to register a pre-update hook on a
    ** database handle that has one or more session objects attached. Nor is
    ** it possible to create a session object attached to a database handle for
    ** which a pre-update hook is already defined. The results of attempting
    ** either of these things are undefined.
    **
    ** The session object will be used to create changesets for tables in
    ** database zDb, where zDb is either "main", or "temp", or the name of an
    ** attached database. It is not an error if database zDb is not attached
    ** to the database when the session object is created.
    */
    SQLITE_API int sqlite3session_create(
        sqlite3* db,                    /* Database handle */
        const char* zDb,                /* Name of db (e.g. "main") */
        sqlite3_session** ppSession     /* OUT: New session object */
    );

    /*
    ** CAPI3REF: Delete A Session Object
    ** DESTRUCTOR: sqlite3_session
    **
    ** Delete a session object previously allocated using
    ** [sqlite3session_create()]. Once a session object has been deleted, the
    ** results of attempting to use pSession with any other session module
    ** function are undefined.
    **
    ** Session objects must be deleted before the database handle to which they
    ** are attached is closed. Refer to the documentation for
    ** [sqlite3session_create()] for details.
    */
    SQLITE_API void sqlite3session_delete(sqlite3_session* pSession);


    /*
    ** CAPI3REF: Enable Or Disable A Session Object
    ** METHOD: sqlite3_session
    **
    ** Enable or disable the recording of changes by a session object. When
    ** enabled, a session object records changes made to the database. When
    ** disabled - it does not. A newly created session object is enabled.
    ** Refer to the documentation for [sqlite3session_changeset()] for further
    ** details regarding how enabling and disabling a session object affects
    ** the eventual changesets.
    **
    ** Passing zero to this function disables the session. Passing a value
    ** greater than zero enables it. Passing a value less than zero is a
    ** no-op, and may be used to query the current state of the session.
    **
    ** The return value indicates the final state of the session object: 0 if
    ** the session is disabled, or 1 if it is enabled.
    */
    SQLITE_API int sqlite3session_enable(sqlite3_session* pSession, int bEnable);

    /*
    ** CAPI3REF: Set Or Clear the Indirect Change Flag
    ** METHOD: sqlite3_session
    **
    ** Each change recorded by a session object is marked as either direct or
    ** indirect. A change is marked as indirect if either:
    **
    ** <ul>
    **   <li> The session object "indirect" flag is set when the change is
    **        made, or
    **   <li> The change is made by an SQL trigger or foreign key action
    **        instead of directly as a result of a users SQL statement.
    ** </ul>
    **
    ** If a single row is affected by more than one operation within a session,
    ** then the change is considered indirect if all operations meet the criteria
    ** for an indirect change above, or direct otherwise.
    **
    ** This function is used to set, clear or query the session object indirect
    ** flag.  If the second argument passed to this function is zero, then the
    ** indirect flag is cleared. If it is greater than zero, the indirect flag
    ** is set. Passing a value less than zero does not modify the current value
    ** of the indirect flag, and may be used to query the current state of the
    ** indirect flag for the specified session object.
    **
    ** The return value indicates the final state of the indirect flag: 0 if
    ** it is clear, or 1 if it is set.
    */
    SQLITE_API int sqlite3session_indirect(sqlite3_session* pSession, int bIndirect);

    /*
    ** CAPI3REF: Attach A Table To A Session Object
    ** METHOD: sqlite3_session
    **
    ** If argument zTab is not NULL, then it is the name of a table to attach
    ** to the session object passed as the first argument. All subsequent changes
    ** made to the table while the session object is enabled will be recorded. See
    ** documentation for [sqlite3session_changeset()] for further details.
    **
    ** Or, if argument zTab is NULL, then changes are recorded for all tables
    ** in the database. If additional tables are added to the database (by
    ** executing "CREATE TABLE" statements) after this call is made, changes for
    ** the new tables are also recorded.
    **
    ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly
    ** defined as part of their CREATE TABLE statement. It does not matter if the
    ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY
    ** KEY may consist of a single column, or may be a composite key.
    **
    ** It is not an error if the named table does not exist in the database. Nor
    ** is it an error if the named table does not have a PRIMARY KEY. However,
    ** no changes will be recorded in either of these scenarios.
    **
    ** Changes are not recorded for individual rows that have NULL values stored
    ** in one or more of their PRIMARY KEY columns.
    **
    ** SQLITE_OK is returned if the call completes without error. Or, if an error
    ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
    **
    ** <h3>Special sqlite_stat1 Handling</h3>
    **
    ** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to
    ** some of the rules above. In SQLite, the schema of sqlite_stat1 is:
    **  <pre>
    **  &nbsp;     CREATE TABLE sqlite_stat1(tbl,idx,stat)
    **  </pre>
    **
    ** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are
    ** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes
    ** are recorded for rows for which (idx IS NULL) is true. However, for such
    ** rows a zero-length blob (SQL value X'') is stored in the changeset or
    ** patchset instead of a NULL value. This allows such changesets to be
    ** manipulated by legacy implementations of sqlite3changeset_invert(),
    ** concat() and similar.
    **
    ** The sqlite3changeset_apply() function automatically converts the
    ** zero-length blob back to a NULL value when updating the sqlite_stat1
    ** table. However, if the application calls sqlite3changeset_new(),
    ** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset
    ** iterator directly (including on a changeset iterator passed to a
    ** conflict-handler callback) then the X'' value is returned. The application
    ** must translate X'' to NULL itself if required.
    **
    ** Legacy (older than 3.22.0) versions of the sessions module cannot capture
    ** changes made to the sqlite_stat1 table. Legacy versions of the
    ** sqlite3changeset_apply() function silently ignore any modifications to the
    ** sqlite_stat1 table that are part of a changeset or patchset.
    */
    SQLITE_API int sqlite3session_attach(
        sqlite3_session* pSession,      /* Session object */
        const char* zTab                /* Table name */
    );

    /*
    ** CAPI3REF: Set a table filter on a Session Object.
    ** METHOD: sqlite3_session
    **
    ** The second argument (xFilter) is the "filter callback". For changes to rows
    ** in tables that are not attached to the Session object, the filter is called
    ** to determine whether changes to the table's rows should be tracked or not.
    ** If xFilter returns 0, changes are not tracked. Note that once a table is
    ** attached, xFilter will not be called again.
    */
    SQLITE_API void sqlite3session_table_filter(
        sqlite3_session* pSession,      /* Session object */
        int(*xFilter)(
            void* pCtx,                   /* Copy of third arg to _filter_table() */
            const char* zTab              /* Table name */
            ),
        void* pCtx                      /* First argument passed to xFilter */
    );

    /*
    ** CAPI3REF: Generate A Changeset From A Session Object
    ** METHOD: sqlite3_session
    **
    ** Obtain a changeset containing changes to the tables attached to the
    ** session object passed as the first argument. If successful,
    ** set *ppChangeset to point to a buffer containing the changeset
    ** and *pnChangeset to the size of the changeset in bytes before returning
    ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to
    ** zero and return an SQLite error code.
    **
    ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,
    ** each representing a change to a single row of an attached table. An INSERT
    ** change contains the values of each field of a new database row. A DELETE
    ** contains the original values of each field of a deleted database row. An
    ** UPDATE change contains the original values of each field of an updated
    ** database row along with the updated values for each updated non-primary-key
    ** column. It is not possible for an UPDATE change to represent a change that
    ** modifies the values of primary key columns. If such a change is made, it
    ** is represented in a changeset as a DELETE followed by an INSERT.
    **
    ** Changes are not recorded for rows that have NULL values stored in one or
    ** more of their PRIMARY KEY columns. If such a row is inserted or deleted,
    ** no corresponding change is present in the changesets returned by this
    ** function. If an existing row with one or more NULL values stored in
    ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,
    ** only an INSERT is appears in the changeset. Similarly, if an existing row
    ** with non-NULL PRIMARY KEY values is updated so that one or more of its
    ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a
    ** DELETE change only.
    **
    ** The contents of a changeset may be traversed using an iterator created
    ** using the [sqlite3changeset_start()] API. A changeset may be applied to
    ** a database with a compatible schema using the [sqlite3changeset_apply()]
    ** API.
    **
    ** Within a changeset generated by this function, all changes related to a
    ** single table are grouped together. In other words, when iterating through
    ** a changeset or when applying a changeset to a database, all changes related
    ** to a single table are processed before moving on to the next table. Tables
    ** are sorted in the same order in which they were attached (or auto-attached)
    ** to the sqlite3_session object. The order in which the changes related to
    ** a single table are stored is undefined.
    **
    ** Following a successful call to this function, it is the responsibility of
    ** the caller to eventually free the buffer that *ppChangeset points to using
    ** [sqlite3_free()].
    **
    ** <h3>Changeset Generation</h3>
    **
    ** Once a table has been attached to a session object, the session object
    ** records the primary key values of all new rows inserted into the table.
    ** It also records the original primary key and other column values of any
    ** deleted or updated rows. For each unique primary key value, data is only
    ** recorded once - the first time a row with said primary key is inserted,
    ** updated or deleted in the lifetime of the session.
    **
    ** There is one exception to the previous paragraph: when a row is inserted,
    ** updated or deleted, if one or more of its primary key columns contain a
    ** NULL value, no record of the change is made.
    **
    ** The session object therefore accumulates two types of records - those
    ** that consist of primary key values only (created when the user inserts
    ** a new record) and those that consist of the primary key values and the
    ** original values of other table columns (created when the users deletes
    ** or updates a record).
    **
    ** When this function is called, the requested changeset is created using
    ** both the accumulated records and the current contents of the database
    ** file. Specifically:
    **
    ** <ul>
    **   <li> For each record generated by an insert, the database is queried
    **        for a row with a matching primary key. If one is found, an INSERT
    **        change is added to the changeset. If no such row is found, no change
    **        is added to the changeset.
    **
    **   <li> For each record generated by an update or delete, the database is
    **        queried for a row with a matching primary key. If such a row is
    **        found and one or more of the non-primary key fields have been
    **        modified from their original values, an UPDATE change is added to
    **        the changeset. Or, if no such row is found in the table, a DELETE
    **        change is added to the changeset. If there is a row with a matching
    **        primary key in the database, but all fields contain their original
    **        values, no change is added to the changeset.
    ** </ul>
    **
    ** This means, amongst other things, that if a row is inserted and then later
    ** deleted while a session object is active, neither the insert nor the delete
    ** will be present in the changeset. Or if a row is deleted and then later a
    ** row with the same primary key values inserted while a session object is
    ** active, the resulting changeset will contain an UPDATE change instead of
    ** a DELETE and an INSERT.
    **
    ** When a session object is disabled (see the [sqlite3session_enable()] API),
    ** it does not accumulate records when rows are inserted, updated or deleted.
    ** This may appear to have some counter-intuitive effects if a single row
    ** is written to more than once during a session. For example, if a row
    ** is inserted while a session object is enabled, then later deleted while
    ** the same session object is disabled, no INSERT record will appear in the
    ** changeset, even though the delete took place while the session was disabled.
    ** Or, if one field of a row is updated while a session is disabled, and
    ** another field of the same row is updated while the session is enabled, the
    ** resulting changeset will contain an UPDATE change that updates both fields.
    */
    SQLITE_API int sqlite3session_changeset(
        sqlite3_session* pSession,      /* Session object */
        int* pnChangeset,               /* OUT: Size of buffer at *ppChangeset */
        void** ppChangeset              /* OUT: Buffer containing changeset */
    );

    /*
    ** CAPI3REF: Load The Difference Between Tables Into A Session
    ** METHOD: sqlite3_session
    **
    ** If it is not already attached to the session object passed as the first
    ** argument, this function attaches table zTbl in the same manner as the
    ** [sqlite3session_attach()] function. If zTbl does not exist, or if it
    ** does not have a primary key, this function is a no-op (but does not return
    ** an error).
    **
    ** Argument zFromDb must be the name of a database ("main", "temp" etc.)
    ** attached to the same database handle as the session object that contains
    ** a table compatible with the table attached to the session by this function.
    ** A table is considered compatible if it:
    **
    ** <ul>
    **   <li> Has the same name,
    **   <li> Has the same set of columns declared in the same order, and
    **   <li> Has the same PRIMARY KEY definition.
    ** </ul>
    **
    ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables
    ** are compatible but do not have any PRIMARY KEY columns, it is not an error
    ** but no changes are added to the session object. As with other session
    ** APIs, tables without PRIMARY KEYs are simply ignored.
    **
    ** This function adds a set of changes to the session object that could be
    ** used to update the table in database zFrom (call this the "from-table")
    ** so that its content is the same as the table attached to the session
    ** object (call this the "to-table"). Specifically:
    **
    ** <ul>
    **   <li> For each row (primary key) that exists in the to-table but not in
    **     the from-table, an INSERT record is added to the session object.
    **
    **   <li> For each row (primary key) that exists in the to-table but not in
    **     the from-table, a DELETE record is added to the session object.
    **
    **   <li> For each row (primary key) that exists in both tables, but features
    **     different non-PK values in each, an UPDATE record is added to the
    **     session.
    ** </ul>
    **
    ** To clarify, if this function is called and then a changeset constructed
    ** using [sqlite3session_changeset()], then after applying that changeset to
    ** database zFrom the contents of the two compatible tables would be
    ** identical.
    **
    ** It an error if database zFrom does not exist or does not contain the
    ** required compatible table.
    **
    ** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite
    ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg
    ** may be set to point to a buffer containing an English language error
    ** message. It is the responsibility of the caller to free this buffer using
    ** sqlite3_free().
    */
    SQLITE_API int sqlite3session_diff(
        sqlite3_session* pSession,
        const char* zFromDb,
        const char* zTbl,
        char** pzErrMsg
    );


    /*
    ** CAPI3REF: Generate A Patchset From A Session Object
    ** METHOD: sqlite3_session
    **
    ** The differences between a patchset and a changeset are that:
    **
    ** <ul>
    **   <li> DELETE records consist of the primary key fields only. The
    **        original values of other fields are omitted.
    **   <li> The original values of any modified fields are omitted from
    **        UPDATE records.
    ** </ul>
    **
    ** A patchset blob may be used with up to date versions of all
    ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(),
    ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly,
    ** attempting to use a patchset blob with old versions of the
    ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error.
    **
    ** Because the non-primary key "old.*" fields are omitted, no
    ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset
    ** is passed to the sqlite3changeset_apply() API. Other conflict types work
    ** in the same way as for changesets.
    **
    ** Changes within a patchset are ordered in the same way as for changesets
    ** generated by the sqlite3session_changeset() function (i.e. all changes for
    ** a single table are grouped together, tables appear in the order in which
    ** they were attached to the session object).
    */
    SQLITE_API int sqlite3session_patchset(
        sqlite3_session* pSession,      /* Session object */
        int* pnPatchset,                /* OUT: Size of buffer at *ppPatchset */
        void** ppPatchset               /* OUT: Buffer containing patchset */
    );

    /*
    ** CAPI3REF: Test if a changeset has recorded any changes.
    **
    ** Return non-zero if no changes to attached tables have been recorded by
    ** the session object passed as the first argument. Otherwise, if one or
    ** more changes have been recorded, return zero.
    **
    ** Even if this function returns zero, it is possible that calling
    ** [sqlite3session_changeset()] on the session handle may still return a
    ** changeset that contains no changes. This can happen when a row in
    ** an attached table is modified and then later on the original values
    ** are restored. However, if this function returns non-zero, then it is
    ** guaranteed that a call to sqlite3session_changeset() will return a
    ** changeset containing zero changes.
    */
    SQLITE_API int sqlite3session_isempty(sqlite3_session* pSession);

    /*
    ** CAPI3REF: Query for the amount of heap memory used by a session object.
    **
    ** This API returns the total amount of heap memory in bytes currently
    ** used by the session object passed as the only argument.
    */
    SQLITE_API sqlite3_int64 sqlite3session_memory_used(sqlite3_session* pSession);

    /*
    ** CAPI3REF: Create An Iterator To Traverse A Changeset
    ** CONSTRUCTOR: sqlite3_changeset_iter
    **
    ** Create an iterator used to iterate through the contents of a changeset.
    ** If successful, *pp is set to point to the iterator handle and SQLITE_OK
    ** is returned. Otherwise, if an error occurs, *pp is set to zero and an
    ** SQLite error code is returned.
    **
    ** The following functions can be used to advance and query a changeset
    ** iterator created by this function:
    **
    ** <ul>
    **   <li> [sqlite3changeset_next()]
    **   <li> [sqlite3changeset_op()]
    **   <li> [sqlite3changeset_new()]
    **   <li> [sqlite3changeset_old()]
    ** </ul>
    **
    ** It is the responsibility of the caller to eventually destroy the iterator
    ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the
    ** changeset (pChangeset) must remain valid until after the iterator is
    ** destroyed.
    **
    ** Assuming the changeset blob was created by one of the
    ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or
    ** [sqlite3changeset_invert()] functions, all changes within the changeset
    ** that apply to a single table are grouped together. This means that when
    ** an application iterates through a changeset using an iterator created by
    ** this function, all changes that relate to a single table are visited
    ** consecutively. There is no chance that the iterator will visit a change
    ** the applies to table X, then one for table Y, and then later on visit
    ** another change for table X.
    **
    ** The behavior of sqlite3changeset_start_v2() and its streaming equivalent
    ** may be modified by passing a combination of
    ** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter.
    **
    ** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b>
    ** and therefore subject to change.
    */
    SQLITE_API int sqlite3changeset_start(
        sqlite3_changeset_iter** pp,    /* OUT: New changeset iterator handle */
        int nChangeset,                 /* Size of changeset blob in bytes */
        void* pChangeset                /* Pointer to blob containing changeset */
    );
    SQLITE_API int sqlite3changeset_start_v2(
        sqlite3_changeset_iter** pp,    /* OUT: New changeset iterator handle */
        int nChangeset,                 /* Size of changeset blob in bytes */
        void* pChangeset,               /* Pointer to blob containing changeset */
        int flags                       /* SESSION_CHANGESETSTART_* flags */
    );

    /*
    ** CAPI3REF: Flags for sqlite3changeset_start_v2
    **
    ** The following flags may passed via the 4th parameter to
    ** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]:
    **
    ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
    **   Invert the changeset while iterating through it. This is equivalent to
    **   inverting a changeset using sqlite3changeset_invert() before applying it.
    **   It is an error to specify this flag with a patchset.
    */
#define SQLITE_CHANGESETSTART_INVERT        0x0002


    /*
    ** CAPI3REF: Advance A Changeset Iterator
    ** METHOD: sqlite3_changeset_iter
    **
    ** This function may only be used with iterators created by the function
    ** [sqlite3changeset_start()]. If it is called on an iterator passed to
    ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE
    ** is returned and the call has no effect.
    **
    ** Immediately after an iterator is created by sqlite3changeset_start(), it
    ** does not point to any change in the changeset. Assuming the changeset
    ** is not empty, the first call to this function advances the iterator to
    ** point to the first change in the changeset. Each subsequent call advances
    ** the iterator to point to the next change in the changeset (if any). If
    ** no error occurs and the iterator points to a valid change after a call
    ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned.
    ** Otherwise, if all changes in the changeset have already been visited,
    ** SQLITE_DONE is returned.
    **
    ** If an error occurs, an SQLite error code is returned. Possible error
    ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or
    ** SQLITE_NOMEM.
    */
    SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter* pIter);

    /*
    ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
    ** METHOD: sqlite3_changeset_iter
    **
    ** The pIter argument passed to this function may either be an iterator
    ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
    ** created by [sqlite3changeset_start()]. In the latter case, the most recent
    ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
    ** is not the case, this function returns [SQLITE_MISUSE].
    **
    ** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three
    ** outputs are set through these pointers:
    **
    ** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE],
    ** depending on the type of change that the iterator currently points to;
    **
    ** *pnCol is set to the number of columns in the table affected by the change; and
    **
    ** *pzTab is set to point to a nul-terminated utf-8 encoded string containing
    ** the name of the table affected by the current change. The buffer remains
    ** valid until either sqlite3changeset_next() is called on the iterator
    ** or until the conflict-handler function returns.
    **
    ** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change
    ** is an indirect change, or false (0) otherwise. See the documentation for
    ** [sqlite3session_indirect()] for a description of direct and indirect
    ** changes.
    **
    ** If no error occurs, SQLITE_OK is returned. If an error does occur, an
    ** SQLite error code is returned. The values of the output variables may not
    ** be trusted in this case.
    */
    SQLITE_API int sqlite3changeset_op(
        sqlite3_changeset_iter* pIter,  /* Iterator object */
        const char** pzTab,             /* OUT: Pointer to table name */
        int* pnCol,                     /* OUT: Number of columns in table */
        int* pOp,                       /* OUT: SQLITE_INSERT, DELETE or UPDATE */
        int* pbIndirect                 /* OUT: True for an 'indirect' change */
    );

    /*
    ** CAPI3REF: Obtain The Primary Key Definition Of A Table
    ** METHOD: sqlite3_changeset_iter
    **
    ** For each modified table, a changeset includes the following:
    **
    ** <ul>
    **   <li> The number of columns in the table, and
    **   <li> Which of those columns make up the tables PRIMARY KEY.
    ** </ul>
    **
    ** This function is used to find which columns comprise the PRIMARY KEY of
    ** the table modified by the change that iterator pIter currently points to.
    ** If successful, *pabPK is set to point to an array of nCol entries, where
    ** nCol is the number of columns in the table. Elements of *pabPK are set to
    ** 0x01 if the corresponding column is part of the tables primary key, or
    ** 0x00 if it is not.
    **
    ** If argument pnCol is not NULL, then *pnCol is set to the number of columns
    ** in the table.
    **
    ** If this function is called when the iterator does not point to a valid
    ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
    ** SQLITE_OK is returned and the output variables populated as described
    ** above.
    */
    SQLITE_API int sqlite3changeset_pk(
        sqlite3_changeset_iter* pIter,  /* Iterator object */
        unsigned char** pabPK,          /* OUT: Array of boolean - true for PK cols */
        int* pnCol                      /* OUT: Number of entries in output array */
    );

    /*
    ** CAPI3REF: Obtain old.* Values From A Changeset Iterator
    ** METHOD: sqlite3_changeset_iter
    **
    ** The pIter argument passed to this function may either be an iterator
    ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
    ** created by [sqlite3changeset_start()]. In the latter case, the most recent
    ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
    ** Furthermore, it may only be called if the type of change that the iterator
    ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,
    ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
    **
    ** Argument iVal must be greater than or equal to 0, and less than the number
    ** of columns in the table affected by the current change. Otherwise,
    ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
    **
    ** If successful, this function sets *ppValue to point to a protected
    ** sqlite3_value object containing the iVal'th value from the vector of
    ** original row values stored as part of the UPDATE or DELETE change and
    ** returns SQLITE_OK. The name of the function comes from the fact that this
    ** is similar to the "old.*" columns available to update or delete triggers.
    **
    ** If some other error occurs (e.g. an OOM condition), an SQLite error code
    ** is returned and *ppValue is set to NULL.
    */
    SQLITE_API int sqlite3changeset_old(
        sqlite3_changeset_iter* pIter,  /* Changeset iterator */
        int iVal,                       /* Column number */
        sqlite3_value** ppValue         /* OUT: Old value (or NULL pointer) */
    );

    /*
    ** CAPI3REF: Obtain new.* Values From A Changeset Iterator
    ** METHOD: sqlite3_changeset_iter
    **
    ** The pIter argument passed to this function may either be an iterator
    ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
    ** created by [sqlite3changeset_start()]. In the latter case, the most recent
    ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
    ** Furthermore, it may only be called if the type of change that the iterator
    ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,
    ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
    **
    ** Argument iVal must be greater than or equal to 0, and less than the number
    ** of columns in the table affected by the current change. Otherwise,
    ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
    **
    ** If successful, this function sets *ppValue to point to a protected
    ** sqlite3_value object containing the iVal'th value from the vector of
    ** new row values stored as part of the UPDATE or INSERT change and
    ** returns SQLITE_OK. If the change is an UPDATE and does not include
    ** a new value for the requested column, *ppValue is set to NULL and
    ** SQLITE_OK returned. The name of the function comes from the fact that
    ** this is similar to the "new.*" columns available to update or delete
    ** triggers.
    **
    ** If some other error occurs (e.g. an OOM condition), an SQLite error code
    ** is returned and *ppValue is set to NULL.
    */
    SQLITE_API int sqlite3changeset_new(
        sqlite3_changeset_iter* pIter,  /* Changeset iterator */
        int iVal,                       /* Column number */
        sqlite3_value** ppValue         /* OUT: New value (or NULL pointer) */
    );

    /*
    ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator
    ** METHOD: sqlite3_changeset_iter
    **
    ** This function should only be used with iterator objects passed to a
    ** conflict-handler callback by [sqlite3changeset_apply()] with either
    ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function
    ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue
    ** is set to NULL.
    **
    ** Argument iVal must be greater than or equal to 0, and less than the number
    ** of columns in the table affected by the current change. Otherwise,
    ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
    **
    ** If successful, this function sets *ppValue to point to a protected
    ** sqlite3_value object containing the iVal'th value from the
    ** "conflicting row" associated with the current conflict-handler callback
    ** and returns SQLITE_OK.
    **
    ** If some other error occurs (e.g. an OOM condition), an SQLite error code
    ** is returned and *ppValue is set to NULL.
    */
    SQLITE_API int sqlite3changeset_conflict(
        sqlite3_changeset_iter* pIter,  /* Changeset iterator */
        int iVal,                       /* Column number */
        sqlite3_value** ppValue         /* OUT: Value from conflicting row */
    );

    /*
    ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
    ** METHOD: sqlite3_changeset_iter
    **
    ** This function may only be called with an iterator passed to an
    ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
    ** it sets the output variable to the total number of known foreign key
    ** violations in the destination database and returns SQLITE_OK.
    **
    ** In all other cases this function returns SQLITE_MISUSE.
    */
    SQLITE_API int sqlite3changeset_fk_conflicts(
        sqlite3_changeset_iter* pIter,  /* Changeset iterator */
        int* pnOut                      /* OUT: Number of FK violations */
    );


    /*
    ** CAPI3REF: Finalize A Changeset Iterator
    ** METHOD: sqlite3_changeset_iter
    **
    ** This function is used to finalize an iterator allocated with
    ** [sqlite3changeset_start()].
    **
    ** This function should only be called on iterators created using the
    ** [sqlite3changeset_start()] function. If an application calls this
    ** function with an iterator passed to a conflict-handler by
    ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the
    ** call has no effect.
    **
    ** If an error was encountered within a call to an sqlite3changeset_xxx()
    ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an
    ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding
    ** to that error is returned by this function. Otherwise, SQLITE_OK is
    ** returned. This is to allow the following pattern (pseudo-code):
    **
    ** <pre>
    **   sqlite3changeset_start();
    **   while( SQLITE_ROW==sqlite3changeset_next() ){
    **     // Do something with change.
    **   }
    **   rc = sqlite3changeset_finalize();
    **   if( rc!=SQLITE_OK ){
    **     // An error has occurred
    **   }
    ** </pre>
    */
    SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter* pIter);

    /*
    ** CAPI3REF: Invert A Changeset
    **
    ** This function is used to "invert" a changeset object. Applying an inverted
    ** changeset to a database reverses the effects of applying the uninverted
    ** changeset. Specifically:
    **
    ** <ul>
    **   <li> Each DELETE change is changed to an INSERT, and
    **   <li> Each INSERT change is changed to a DELETE, and
    **   <li> For each UPDATE change, the old.* and new.* values are exchanged.
    ** </ul>
    **
    ** This function does not change the order in which changes appear within
    ** the changeset. It merely reverses the sense of each individual change.
    **
    ** If successful, a pointer to a buffer containing the inverted changeset
    ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and
    ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are
    ** zeroed and an SQLite error code returned.
    **
    ** It is the responsibility of the caller to eventually call sqlite3_free()
    ** on the *ppOut pointer to free the buffer allocation following a successful
    ** call to this function.
    **
    ** WARNING/TODO: This function currently assumes that the input is a valid
    ** changeset. If it is not, the results are undefined.
    */
    SQLITE_API int sqlite3changeset_invert(
        int nIn, const void* pIn,       /* Input changeset */
        int* pnOut, void** ppOut        /* OUT: Inverse of input */
    );

    /*
    ** CAPI3REF: Concatenate Two Changeset Objects
    **
    ** This function is used to concatenate two changesets, A and B, into a
    ** single changeset. The result is a changeset equivalent to applying
    ** changeset A followed by changeset B.
    **
    ** This function combines the two input changesets using an
    ** sqlite3_changegroup object. Calling it produces similar results as the
    ** following code fragment:
    **
    ** <pre>
    **   sqlite3_changegroup *pGrp;
    **   rc = sqlite3_changegroup_new(&pGrp);
    **   if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA);
    **   if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB);
    **   if( rc==SQLITE_OK ){
    **     rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);
    **   }else{
    **     *ppOut = 0;
    **     *pnOut = 0;
    **   }
    ** </pre>
    **
    ** Refer to the sqlite3_changegroup documentation below for details.
    */
    SQLITE_API int sqlite3changeset_concat(
        int nA,                         /* Number of bytes in buffer pA */
        void* pA,                       /* Pointer to buffer containing changeset A */
        int nB,                         /* Number of bytes in buffer pB */
        void* pB,                       /* Pointer to buffer containing changeset B */
        int* pnOut,                     /* OUT: Number of bytes in output changeset */
        void** ppOut                    /* OUT: Buffer containing output changeset */
    );


    /*
    ** CAPI3REF: Changegroup Handle
    **
    ** A changegroup is an object used to combine two or more
    ** [changesets] or [patchsets]
    */
    typedef struct sqlite3_changegroup sqlite3_changegroup;

    /*
    ** CAPI3REF: Create A New Changegroup Object
    ** CONSTRUCTOR: sqlite3_changegroup
    **
    ** An sqlite3_changegroup object is used to combine two or more changesets
    ** (or patchsets) into a single changeset (or patchset). A single changegroup
    ** object may combine changesets or patchsets, but not both. The output is
    ** always in the same format as the input.
    **
    ** If successful, this function returns SQLITE_OK and populates (*pp) with
    ** a pointer to a new sqlite3_changegroup object before returning. The caller
    ** should eventually free the returned object using a call to
    ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code
    ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.
    **
    ** The usual usage pattern for an sqlite3_changegroup object is as follows:
    **
    ** <ul>
    **   <li> It is created using a call to sqlite3changegroup_new().
    **
    **   <li> Zero or more changesets (or patchsets) are added to the object
    **        by calling sqlite3changegroup_add().
    **
    **   <li> The result of combining all input changesets together is obtained
    **        by the application via a call to sqlite3changegroup_output().
    **
    **   <li> The object is deleted using a call to sqlite3changegroup_delete().
    ** </ul>
    **
    ** Any number of calls to add() and output() may be made between the calls to
    ** new() and delete(), and in any order.
    **
    ** As well as the regular sqlite3changegroup_add() and
    ** sqlite3changegroup_output() functions, also available are the streaming
    ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().
    */
    SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup** pp);

    /*
    ** CAPI3REF: Add A Changeset To A Changegroup
    ** METHOD: sqlite3_changegroup
    **
    ** Add all changes within the changeset (or patchset) in buffer pData (size
    ** nData bytes) to the changegroup.
    **
    ** If the buffer contains a patchset, then all prior calls to this function
    ** on the same changegroup object must also have specified patchsets. Or, if
    ** the buffer contains a changeset, so must have the earlier calls to this
    ** function. Otherwise, SQLITE_ERROR is returned and no changes are added
    ** to the changegroup.
    **
    ** Rows within the changeset and changegroup are identified by the values in
    ** their PRIMARY KEY columns. A change in the changeset is considered to
    ** apply to the same row as a change already present in the changegroup if
    ** the two rows have the same primary key.
    **
    ** Changes to rows that do not already appear in the changegroup are
    ** simply copied into it. Or, if both the new changeset and the changegroup
    ** contain changes that apply to a single row, the final contents of the
    ** changegroup depends on the type of each change, as follows:
    **
    ** <table border=1 style="margin-left:8ex;margin-right:8ex">
    **   <tr><th style="white-space:pre">Existing Change  </th>
    **       <th style="white-space:pre">New Change       </th>
    **       <th>Output Change
    **   <tr><td>INSERT <td>INSERT <td>
    **       The new change is ignored. This case does not occur if the new
    **       changeset was recorded immediately after the changesets already
    **       added to the changegroup.
    **   <tr><td>INSERT <td>UPDATE <td>
    **       The INSERT change remains in the changegroup. The values in the
    **       INSERT change are modified as if the row was inserted by the
    **       existing change and then updated according to the new change.
    **   <tr><td>INSERT <td>DELETE <td>
    **       The existing INSERT is removed from the changegroup. The DELETE is
    **       not added.
    **   <tr><td>UPDATE <td>INSERT <td>
    **       The new change is ignored. This case does not occur if the new
    **       changeset was recorded immediately after the changesets already
    **       added to the changegroup.
    **   <tr><td>UPDATE <td>UPDATE <td>
    **       The existing UPDATE remains within the changegroup. It is amended
    **       so that the accompanying values are as if the row was updated once
    **       by the existing change and then again by the new change.
    **   <tr><td>UPDATE <td>DELETE <td>
    **       The existing UPDATE is replaced by the new DELETE within the
    **       changegroup.
    **   <tr><td>DELETE <td>INSERT <td>
    **       If one or more of the column values in the row inserted by the
    **       new change differ from those in the row deleted by the existing
    **       change, the existing DELETE is replaced by an UPDATE within the
    **       changegroup. Otherwise, if the inserted row is exactly the same
    **       as the deleted row, the existing DELETE is simply discarded.
    **   <tr><td>DELETE <td>UPDATE <td>
    **       The new change is ignored. This case does not occur if the new
    **       changeset was recorded immediately after the changesets already
    **       added to the changegroup.
    **   <tr><td>DELETE <td>DELETE <td>
    **       The new change is ignored. This case does not occur if the new
    **       changeset was recorded immediately after the changesets already
    **       added to the changegroup.
    ** </table>
    **
    ** If the new changeset contains changes to a table that is already present
    ** in the changegroup, then the number of columns and the position of the
    ** primary key columns for the table must be consistent. If this is not the
    ** case, this function fails with SQLITE_SCHEMA. If the input changeset
    ** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is
    ** returned. Or, if an out-of-memory condition occurs during processing, this
    ** function returns SQLITE_NOMEM. In all cases, if an error occurs the state
    ** of the final contents of the changegroup is undefined.
    **
    ** If no error occurs, SQLITE_OK is returned.
    */
    SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void* pData);

    /*
    ** CAPI3REF: Obtain A Composite Changeset From A Changegroup
    ** METHOD: sqlite3_changegroup
    **
    ** Obtain a buffer containing a changeset (or patchset) representing the
    ** current contents of the changegroup. If the inputs to the changegroup
    ** were themselves changesets, the output is a changeset. Or, if the
    ** inputs were patchsets, the output is also a patchset.
    **
    ** As with the output of the sqlite3session_changeset() and
    ** sqlite3session_patchset() functions, all changes related to a single
    ** table are grouped together in the output of this function. Tables appear
    ** in the same order as for the very first changeset added to the changegroup.
    ** If the second or subsequent changesets added to the changegroup contain
    ** changes for tables that do not appear in the first changeset, they are
    ** appended onto the end of the output changeset, again in the order in
    ** which they are first encountered.
    **
    ** If an error occurs, an SQLite error code is returned and the output
    ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK
    ** is returned and the output variables are set to the size of and a
    ** pointer to the output buffer, respectively. In this case it is the
    ** responsibility of the caller to eventually free the buffer using a
    ** call to sqlite3_free().
    */
    SQLITE_API int sqlite3changegroup_output(
        sqlite3_changegroup*,
        int* pnData,                    /* OUT: Size of output buffer in bytes */
        void** ppData                   /* OUT: Pointer to output buffer */
    );

    /*
    ** CAPI3REF: Delete A Changegroup Object
    ** DESTRUCTOR: sqlite3_changegroup
    */
    SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*);

    /*
    ** CAPI3REF: Apply A Changeset To A Database
    **
    ** Apply a changeset or patchset to a database. These functions attempt to
    ** update the "main" database attached to handle db with the changes found in
    ** the changeset passed via the second and third arguments.
    **
    ** The fourth argument (xFilter) passed to these functions is the "filter
    ** callback". If it is not NULL, then for each table affected by at least one
    ** change in the changeset, the filter callback is invoked with
    ** the table name as the second argument, and a copy of the context pointer
    ** passed as the sixth argument as the first. If the "filter callback"
    ** returns zero, then no attempt is made to apply any changes to the table.
    ** Otherwise, if the return value is non-zero or the xFilter argument to
    ** is NULL, all changes related to the table are attempted.
    **
    ** For each table that is not excluded by the filter callback, this function
    ** tests that the target database contains a compatible table. A table is
    ** considered compatible if all of the following are true:
    **
    ** <ul>
    **   <li> The table has the same name as the name recorded in the
    **        changeset, and
    **   <li> The table has at least as many columns as recorded in the
    **        changeset, and
    **   <li> The table has primary key columns in the same position as
    **        recorded in the changeset.
    ** </ul>
    **
    ** If there is no compatible table, it is not an error, but none of the
    ** changes associated with the table are applied. A warning message is issued
    ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most
    ** one such warning is issued for each table in the changeset.
    **
    ** For each change for which there is a compatible table, an attempt is made
    ** to modify the table contents according to the UPDATE, INSERT or DELETE
    ** change. If a change cannot be applied cleanly, the conflict handler
    ** function passed as the fifth argument to sqlite3changeset_apply() may be
    ** invoked. A description of exactly when the conflict handler is invoked for
    ** each type of change is below.
    **
    ** Unlike the xFilter argument, xConflict may not be passed NULL. The results
    ** of passing anything other than a valid function pointer as the xConflict
    ** argument are undefined.
    **
    ** Each time the conflict handler function is invoked, it must return one
    ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or
    ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned
    ** if the second argument passed to the conflict handler is either
    ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler
    ** returns an illegal value, any changes already made are rolled back and
    ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different
    ** actions are taken by sqlite3changeset_apply() depending on the value
    ** returned by each invocation of the conflict-handler function. Refer to
    ** the documentation for the three
    ** [SQLITE_CHANGESET_OMIT|available return values] for details.
    **
    ** <dl>
    ** <dt>DELETE Changes<dd>
    **   For each DELETE change, the function checks if the target database
    **   contains a row with the same primary key value (or values) as the
    **   original row values stored in the changeset. If it does, and the values
    **   stored in all non-primary key columns also match the values stored in
    **   the changeset the row is deleted from the target database.
    **
    **   If a row with matching primary key values is found, but one or more of
    **   the non-primary key fields contains a value different from the original
    **   row value stored in the changeset, the conflict-handler function is
    **   invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the
    **   database table has more columns than are recorded in the changeset,
    **   only the values of those non-primary key fields are compared against
    **   the current database contents - any trailing database table columns
    **   are ignored.
    **
    **   If no row with matching primary key values is found in the database,
    **   the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
    **   passed as the second argument.
    **
    **   If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT
    **   (which can only happen if a foreign key constraint is violated), the
    **   conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]
    **   passed as the second argument. This includes the case where the DELETE
    **   operation is attempted because an earlier call to the conflict handler
    **   function returned [SQLITE_CHANGESET_REPLACE].
    **
    ** <dt>INSERT Changes<dd>
    **   For each INSERT change, an attempt is made to insert the new row into
    **   the database. If the changeset row contains fewer fields than the
    **   database table, the trailing fields are populated with their default
    **   values.
    **
    **   If the attempt to insert the row fails because the database already
    **   contains a row with the same primary key values, the conflict handler
    **   function is invoked with the second argument set to
    **   [SQLITE_CHANGESET_CONFLICT].
    **
    **   If the attempt to insert the row fails because of some other constraint
    **   violation (e.g. NOT NULL or UNIQUE), the conflict handler function is
    **   invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].
    **   This includes the case where the INSERT operation is re-attempted because
    **   an earlier call to the conflict handler function returned
    **   [SQLITE_CHANGESET_REPLACE].
    **
    ** <dt>UPDATE Changes<dd>
    **   For each UPDATE change, the function checks if the target database
    **   contains a row with the same primary key value (or values) as the
    **   original row values stored in the changeset. If it does, and the values
    **   stored in all modified non-primary key columns also match the values
    **   stored in the changeset the row is updated within the target database.
    **
    **   If a row with matching primary key values is found, but one or more of
    **   the modified non-primary key fields contains a value different from an
    **   original row value stored in the changeset, the conflict-handler function
    **   is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since
    **   UPDATE changes only contain values for non-primary key fields that are
    **   to be modified, only those fields need to match the original values to
    **   avoid the SQLITE_CHANGESET_DATA conflict-handler callback.
    **
    **   If no row with matching primary key values is found in the database,
    **   the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
    **   passed as the second argument.
    **
    **   If the UPDATE operation is attempted, but SQLite returns
    **   SQLITE_CONSTRAINT, the conflict-handler function is invoked with
    **   [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.
    **   This includes the case where the UPDATE operation is attempted after
    **   an earlier call to the conflict handler function returned
    **   [SQLITE_CHANGESET_REPLACE].
    ** </dl>
    **
    ** It is safe to execute SQL statements, including those that write to the
    ** table that the callback related to, from within the xConflict callback.
    ** This can be used to further customize the application's conflict
    ** resolution strategy.
    **
    ** All changes made by these functions are enclosed in a savepoint transaction.
    ** If any other error (aside from a constraint failure when attempting to
    ** write to the target database) occurs, then the savepoint transaction is
    ** rolled back, restoring the target database to its original state, and an
    ** SQLite error code returned.
    **
    ** If the output parameters (ppRebase) and (pnRebase) are non-NULL and
    ** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2()
    ** may set (*ppRebase) to point to a "rebase" that may be used with the
    ** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase)
    ** is set to the size of the buffer in bytes. It is the responsibility of the
    ** caller to eventually free any such buffer using sqlite3_free(). The buffer
    ** is only allocated and populated if one or more conflicts were encountered
    ** while applying the patchset. See comments surrounding the sqlite3_rebaser
    ** APIs for further details.
    **
    ** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent
    ** may be modified by passing a combination of
    ** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter.
    **
    ** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b>
    ** and therefore subject to change.
    */
    SQLITE_API int sqlite3changeset_apply(
        sqlite3* db,                    /* Apply change to "main" db of this handle */
        int nChangeset,                 /* Size of changeset in bytes */
        void* pChangeset,               /* Changeset blob */
        int(*xFilter)(
            void* pCtx,                   /* Copy of sixth arg to _apply() */
            const char* zTab              /* Table name */
            ),
        int(*xConflict)(
            void* pCtx,                   /* Copy of sixth arg to _apply() */
            int eConflict,                /* DATA, MISSING, CONFLICT, CONSTRAINT */
            sqlite3_changeset_iter* p     /* Handle describing change and conflict */
            ),
        void* pCtx                      /* First argument passed to xConflict */
    );
    SQLITE_API int sqlite3changeset_apply_v2(
        sqlite3* db,                    /* Apply change to "main" db of this handle */
        int nChangeset,                 /* Size of changeset in bytes */
        void* pChangeset,               /* Changeset blob */
        int(*xFilter)(
            void* pCtx,                   /* Copy of sixth arg to _apply() */
            const char* zTab              /* Table name */
            ),
        int(*xConflict)(
            void* pCtx,                   /* Copy of sixth arg to _apply() */
            int eConflict,                /* DATA, MISSING, CONFLICT, CONSTRAINT */
            sqlite3_changeset_iter* p     /* Handle describing change and conflict */
            ),
        void* pCtx,                     /* First argument passed to xConflict */
        void** ppRebase, int* pnRebase, /* OUT: Rebase data */
        int flags                       /* SESSION_CHANGESETAPPLY_* flags */
    );

    /*
    ** CAPI3REF: Flags for sqlite3changeset_apply_v2
    **
    ** The following flags may passed via the 9th parameter to
    ** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]:
    **
    ** <dl>
    ** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd>
    **   Usually, the sessions module encloses all operations performed by
    **   a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The
    **   SAVEPOINT is committed if the changeset or patchset is successfully
    **   applied, or rolled back if an error occurs. Specifying this flag
    **   causes the sessions module to omit this savepoint. In this case, if the
    **   caller has an open transaction or savepoint when apply_v2() is called,
    **   it may revert the partially applied changeset by rolling it back.
    **
    ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
    **   Invert the changeset before applying it. This is equivalent to inverting
    **   a changeset using sqlite3changeset_invert() before applying it. It is
    **   an error to specify this flag with a patchset.
    */
#define SQLITE_CHANGESETAPPLY_NOSAVEPOINT   0x0001
#define SQLITE_CHANGESETAPPLY_INVERT        0x0002

    /*
    ** CAPI3REF: Constants Passed To The Conflict Handler
    **
    ** Values that may be passed as the second argument to a conflict-handler.
    **
    ** <dl>
    ** <dt>SQLITE_CHANGESET_DATA<dd>
    **   The conflict handler is invoked with CHANGESET_DATA as the second argument
    **   when processing a DELETE or UPDATE change if a row with the required
    **   PRIMARY KEY fields is present in the database, but one or more other
    **   (non primary-key) fields modified by the update do not contain the
    **   expected "before" values.
    **
    **   The conflicting row, in this case, is the database row with the matching
    **   primary key.
    **
    ** <dt>SQLITE_CHANGESET_NOTFOUND<dd>
    **   The conflict handler is invoked with CHANGESET_NOTFOUND as the second
    **   argument when processing a DELETE or UPDATE change if a row with the
    **   required PRIMARY KEY fields is not present in the database.
    **
    **   There is no conflicting row in this case. The results of invoking the
    **   sqlite3changeset_conflict() API are undefined.
    **
    ** <dt>SQLITE_CHANGESET_CONFLICT<dd>
    **   CHANGESET_CONFLICT is passed as the second argument to the conflict
    **   handler while processing an INSERT change if the operation would result
    **   in duplicate primary key values.
    **
    **   The conflicting row in this case is the database row with the matching
    **   primary key.
    **
    ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>
    **   If foreign key handling is enabled, and applying a changeset leaves the
    **   database in a state containing foreign key violations, the conflict
    **   handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
    **   exactly once before the changeset is committed. If the conflict handler
    **   returns CHANGESET_OMIT, the changes, including those that caused the
    **   foreign key constraint violation, are committed. Or, if it returns
    **   CHANGESET_ABORT, the changeset is rolled back.
    **
    **   No current or conflicting row information is provided. The only function
    **   it is possible to call on the supplied sqlite3_changeset_iter handle
    **   is sqlite3changeset_fk_conflicts().
    **
    ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>
    **   If any other constraint violation occurs while applying a change (i.e.
    **   a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is
    **   invoked with CHANGESET_CONSTRAINT as the second argument.
    **
    **   There is no conflicting row in this case. The results of invoking the
    **   sqlite3changeset_conflict() API are undefined.
    **
    ** </dl>
    */
#define SQLITE_CHANGESET_DATA        1
#define SQLITE_CHANGESET_NOTFOUND    2
#define SQLITE_CHANGESET_CONFLICT    3
#define SQLITE_CHANGESET_CONSTRAINT  4
#define SQLITE_CHANGESET_FOREIGN_KEY 5

    /*
    ** CAPI3REF: Constants Returned By The Conflict Handler
    **
    ** A conflict handler callback must return one of the following three values.
    **
    ** <dl>
    ** <dt>SQLITE_CHANGESET_OMIT<dd>
    **   If a conflict handler returns this value no special action is taken. The
    **   change that caused the conflict is not applied. The session module
    **   continues to the next change in the changeset.
    **
    ** <dt>SQLITE_CHANGESET_REPLACE<dd>
    **   This value may only be returned if the second argument to the conflict
    **   handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this
    **   is not the case, any changes applied so far are rolled back and the
    **   call to sqlite3changeset_apply() returns SQLITE_MISUSE.
    **
    **   If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict
    **   handler, then the conflicting row is either updated or deleted, depending
    **   on the type of change.
    **
    **   If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict
    **   handler, then the conflicting row is removed from the database and a
    **   second attempt to apply the change is made. If this second attempt fails,
    **   the original row is restored to the database before continuing.
    **
    ** <dt>SQLITE_CHANGESET_ABORT<dd>
    **   If this value is returned, any changes applied so far are rolled back
    **   and the call to sqlite3changeset_apply() returns SQLITE_ABORT.
    ** </dl>
    */
#define SQLITE_CHANGESET_OMIT       0
#define SQLITE_CHANGESET_REPLACE    1
#define SQLITE_CHANGESET_ABORT      2

    /*
    ** CAPI3REF: Rebasing changesets
    ** EXPERIMENTAL
    **
    ** Suppose there is a site hosting a database in state S0. And that
    ** modifications are made that move that database to state S1 and a
    ** changeset recorded (the "local" changeset). Then, a changeset based
    ** on S0 is received from another site (the "remote" changeset) and
    ** applied to the database. The database is then in state
    ** (S1+"remote"), where the exact state depends on any conflict
    ** resolution decisions (OMIT or REPLACE) made while applying "remote".
    ** Rebasing a changeset is to update it to take those conflict
    ** resolution decisions into account, so that the same conflicts
    ** do not have to be resolved elsewhere in the network.
    **
    ** For example, if both the local and remote changesets contain an
    ** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)":
    **
    **   local:  INSERT INTO t1 VALUES(1, 'v1');
    **   remote: INSERT INTO t1 VALUES(1, 'v2');
    **
    ** and the conflict resolution is REPLACE, then the INSERT change is
    ** removed from the local changeset (it was overridden). Or, if the
    ** conflict resolution was "OMIT", then the local changeset is modified
    ** to instead contain:
    **
    **           UPDATE t1 SET b = 'v2' WHERE a=1;
    **
    ** Changes within the local changeset are rebased as follows:
    **
    ** <dl>
    ** <dt>Local INSERT<dd>
    **   This may only conflict with a remote INSERT. If the conflict
    **   resolution was OMIT, then add an UPDATE change to the rebased
    **   changeset. Or, if the conflict resolution was REPLACE, add
    **   nothing to the rebased changeset.
    **
    ** <dt>Local DELETE<dd>
    **   This may conflict with a remote UPDATE or DELETE. In both cases the
    **   only possible resolution is OMIT. If the remote operation was a
    **   DELETE, then add no change to the rebased changeset. If the remote
    **   operation was an UPDATE, then the old.* fields of change are updated
    **   to reflect the new.* values in the UPDATE.
    **
    ** <dt>Local UPDATE<dd>
    **   This may conflict with a remote UPDATE or DELETE. If it conflicts
    **   with a DELETE, and the conflict resolution was OMIT, then the update
    **   is changed into an INSERT. Any undefined values in the new.* record
    **   from the update change are filled in using the old.* values from
    **   the conflicting DELETE. Or, if the conflict resolution was REPLACE,
    **   the UPDATE change is simply omitted from the rebased changeset.
    **
    **   If conflict is with a remote UPDATE and the resolution is OMIT, then
    **   the old.* values are rebased using the new.* values in the remote
    **   change. Or, if the resolution is REPLACE, then the change is copied
    **   into the rebased changeset with updates to columns also updated by
    **   the conflicting remote UPDATE removed. If this means no columns would
    **   be updated, the change is omitted.
    ** </dl>
    **
    ** A local change may be rebased against multiple remote changes
    ** simultaneously. If a single key is modified by multiple remote
    ** changesets, they are combined as follows before the local changeset
    ** is rebased:
    **
    ** <ul>
    **    <li> If there has been one or more REPLACE resolutions on a
    **         key, it is rebased according to a REPLACE.
    **
    **    <li> If there have been no REPLACE resolutions on a key, then
    **         the local changeset is rebased according to the most recent
    **         of the OMIT resolutions.
    ** </ul>
    **
    ** Note that conflict resolutions from multiple remote changesets are
    ** combined on a per-field basis, not per-row. This means that in the
    ** case of multiple remote UPDATE operations, some fields of a single
    ** local change may be rebased for REPLACE while others are rebased for
    ** OMIT.
    **
    ** In order to rebase a local changeset, the remote changeset must first
    ** be applied to the local database using sqlite3changeset_apply_v2() and
    ** the buffer of rebase information captured. Then:
    **
    ** <ol>
    **   <li> An sqlite3_rebaser object is created by calling
    **        sqlite3rebaser_create().
    **   <li> The new object is configured with the rebase buffer obtained from
    **        sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure().
    **        If the local changeset is to be rebased against multiple remote
    **        changesets, then sqlite3rebaser_configure() should be called
    **        multiple times, in the same order that the multiple
    **        sqlite3changeset_apply_v2() calls were made.
    **   <li> Each local changeset is rebased by calling sqlite3rebaser_rebase().
    **   <li> The sqlite3_rebaser object is deleted by calling
    **        sqlite3rebaser_delete().
    ** </ol>
    */
    typedef struct sqlite3_rebaser sqlite3_rebaser;

    /*
    ** CAPI3REF: Create a changeset rebaser object.
    ** EXPERIMENTAL
    **
    ** Allocate a new changeset rebaser object. If successful, set (*ppNew) to
    ** point to the new object and return SQLITE_OK. Otherwise, if an error
    ** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew)
    ** to NULL.
    */
    SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser** ppNew);

    /*
    ** CAPI3REF: Configure a changeset rebaser object.
    ** EXPERIMENTAL
    **
    ** Configure the changeset rebaser object to rebase changesets according
    ** to the conflict resolutions described by buffer pRebase (size nRebase
    ** bytes), which must have been obtained from a previous call to
    ** sqlite3changeset_apply_v2().
    */
    SQLITE_API int sqlite3rebaser_configure(
        sqlite3_rebaser*,
        int nRebase, const void* pRebase
    );

    /*
    ** CAPI3REF: Rebase a changeset
    ** EXPERIMENTAL
    **
    ** Argument pIn must point to a buffer containing a changeset nIn bytes
    ** in size. This function allocates and populates a buffer with a copy
    ** of the changeset rebased according to the configuration of the
    ** rebaser object passed as the first argument. If successful, (*ppOut)
    ** is set to point to the new buffer containing the rebased changeset and
    ** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the
    ** responsibility of the caller to eventually free the new buffer using
    ** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut)
    ** are set to zero and an SQLite error code returned.
    */
    SQLITE_API int sqlite3rebaser_rebase(
        sqlite3_rebaser*,
        int nIn, const void* pIn,
        int* pnOut, void** ppOut
    );

    /*
    ** CAPI3REF: Delete a changeset rebaser object.
    ** EXPERIMENTAL
    **
    ** Delete the changeset rebaser object and all associated resources. There
    ** should be one call to this function for each successful invocation
    ** of sqlite3rebaser_create().
    */
    SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser* p);

    /*
    ** CAPI3REF: Streaming Versions of API functions.
    **
    ** The six streaming API xxx_strm() functions serve similar purposes to the
    ** corresponding non-streaming API functions:
    **
    ** <table border=1 style="margin-left:8ex;margin-right:8ex">
    **   <tr><th>Streaming function<th>Non-streaming equivalent</th>
    **   <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply]
    **   <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2]
    **   <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat]
    **   <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert]
    **   <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start]
    **   <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset]
    **   <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset]
    ** </table>
    **
    ** Non-streaming functions that accept changesets (or patchsets) as input
    ** require that the entire changeset be stored in a single buffer in memory.
    ** Similarly, those that return a changeset or patchset do so by returning
    ** a pointer to a single large buffer allocated using sqlite3_malloc().
    ** Normally this is convenient. However, if an application running in a
    ** low-memory environment is required to handle very large changesets, the
    ** large contiguous memory allocations required can become onerous.
    **
    ** In order to avoid this problem, instead of a single large buffer, input
    ** is passed to a streaming API functions by way of a callback function that
    ** the sessions module invokes to incrementally request input data as it is
    ** required. In all cases, a pair of API function parameters such as
    **
    **  <pre>
    **  &nbsp;     int nChangeset,
    **  &nbsp;     void *pChangeset,
    **  </pre>
    **
    ** Is replaced by:
    **
    **  <pre>
    **  &nbsp;     int (*xInput)(void *pIn, void *pData, int *pnData),
    **  &nbsp;     void *pIn,
    **  </pre>
    **
    ** Each time the xInput callback is invoked by the sessions module, the first
    ** argument passed is a copy of the supplied pIn context pointer. The second
    ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no
    ** error occurs the xInput method should copy up to (*pnData) bytes of data
    ** into the buffer and set (*pnData) to the actual number of bytes copied
    ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData)
    ** should be set to zero to indicate this. Or, if an error occurs, an SQLite
    ** error code should be returned. In all cases, if an xInput callback returns
    ** an error, all processing is abandoned and the streaming API function
    ** returns a copy of the error code to the caller.
    **
    ** In the case of sqlite3changeset_start_strm(), the xInput callback may be
    ** invoked by the sessions module at any point during the lifetime of the
    ** iterator. If such an xInput callback returns an error, the iterator enters
    ** an error state, whereby all subsequent calls to iterator functions
    ** immediately fail with the same error code as returned by xInput.
    **
    ** Similarly, streaming API functions that return changesets (or patchsets)
    ** return them in chunks by way of a callback function instead of via a
    ** pointer to a single large buffer. In this case, a pair of parameters such
    ** as:
    **
    **  <pre>
    **  &nbsp;     int *pnChangeset,
    **  &nbsp;     void **ppChangeset,
    **  </pre>
    **
    ** Is replaced by:
    **
    **  <pre>
    **  &nbsp;     int (*xOutput)(void *pOut, const void *pData, int nData),
    **  &nbsp;     void *pOut
    **  </pre>
    **
    ** The xOutput callback is invoked zero or more times to return data to
    ** the application. The first parameter passed to each call is a copy of the
    ** pOut pointer supplied by the application. The second parameter, pData,
    ** points to a buffer nData bytes in size containing the chunk of output
    ** data being returned. If the xOutput callback successfully processes the
    ** supplied data, it should return SQLITE_OK to indicate success. Otherwise,
    ** it should return some other SQLite error code. In this case processing
    ** is immediately abandoned and the streaming API function returns a copy
    ** of the xOutput error code to the application.
    **
    ** The sessions module never invokes an xOutput callback with the third
    ** parameter set to a value less than or equal to zero. Other than this,
    ** no guarantees are made as to the size of the chunks of data returned.
    */
    SQLITE_API int sqlite3changeset_apply_strm(
        sqlite3* db,                    /* Apply change to "main" db of this handle */
        int (*xInput)(void* pIn, void* pData, int* pnData), /* Input function */
        void* pIn,                                          /* First arg for xInput */
        int(*xFilter)(
            void* pCtx,                   /* Copy of sixth arg to _apply() */
            const char* zTab              /* Table name */
            ),
        int(*xConflict)(
            void* pCtx,                   /* Copy of sixth arg to _apply() */
            int eConflict,                /* DATA, MISSING, CONFLICT, CONSTRAINT */
            sqlite3_changeset_iter* p     /* Handle describing change and conflict */
            ),
        void* pCtx                      /* First argument passed to xConflict */
    );
    SQLITE_API int sqlite3changeset_apply_v2_strm(
        sqlite3* db,                    /* Apply change to "main" db of this handle */
        int (*xInput)(void* pIn, void* pData, int* pnData), /* Input function */
        void* pIn,                                          /* First arg for xInput */
        int(*xFilter)(
            void* pCtx,                   /* Copy of sixth arg to _apply() */
            const char* zTab              /* Table name */
            ),
        int(*xConflict)(
            void* pCtx,                   /* Copy of sixth arg to _apply() */
            int eConflict,                /* DATA, MISSING, CONFLICT, CONSTRAINT */
            sqlite3_changeset_iter* p     /* Handle describing change and conflict */
            ),
        void* pCtx,                     /* First argument passed to xConflict */
        void** ppRebase, int* pnRebase,
        int flags
    );
    SQLITE_API int sqlite3changeset_concat_strm(
        int (*xInputA)(void* pIn, void* pData, int* pnData),
        void* pInA,
        int (*xInputB)(void* pIn, void* pData, int* pnData),
        void* pInB,
        int (*xOutput)(void* pOut, const void* pData, int nData),
        void* pOut
    );
    SQLITE_API int sqlite3changeset_invert_strm(
        int (*xInput)(void* pIn, void* pData, int* pnData),
        void* pIn,
        int (*xOutput)(void* pOut, const void* pData, int nData),
        void* pOut
    );
    SQLITE_API int sqlite3changeset_start_strm(
        sqlite3_changeset_iter** pp,
        int (*xInput)(void* pIn, void* pData, int* pnData),
        void* pIn
    );
    SQLITE_API int sqlite3changeset_start_v2_strm(
        sqlite3_changeset_iter** pp,
        int (*xInput)(void* pIn, void* pData, int* pnData),
        void* pIn,
        int flags
    );
    SQLITE_API int sqlite3session_changeset_strm(
        sqlite3_session* pSession,
        int (*xOutput)(void* pOut, const void* pData, int nData),
        void* pOut
    );
    SQLITE_API int sqlite3session_patchset_strm(
        sqlite3_session* pSession,
        int (*xOutput)(void* pOut, const void* pData, int nData),
        void* pOut
    );
    SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*,
        int (*xInput)(void* pIn, void* pData, int* pnData),
        void* pIn
    );
    SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*,
        int (*xOutput)(void* pOut, const void* pData, int nData),
        void* pOut
    );
    SQLITE_API int sqlite3rebaser_rebase_strm(
        sqlite3_rebaser* pRebaser,
        int (*xInput)(void* pIn, void* pData, int* pnData),
        void* pIn,
        int (*xOutput)(void* pOut, const void* pData, int nData),
        void* pOut
    );

    /*
    ** CAPI3REF: Configure global parameters
    **
    ** The sqlite3session_config() interface is used to make global configuration
    ** changes to the sessions module in order to tune it to the specific needs
    ** of the application.
    **
    ** The sqlite3session_config() interface is not threadsafe. If it is invoked
    ** while any other thread is inside any other sessions method then the
    ** results are undefined. Furthermore, if it is invoked after any sessions
    ** related objects have been created, the results are also undefined.
    **
    ** The first argument to the sqlite3session_config() function must be one
    ** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The
    ** interpretation of the (void*) value passed as the second parameter and
    ** the effect of calling this function depends on the value of the first
    ** parameter.
    **
    ** <dl>
    ** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd>
    **    By default, the sessions module streaming interfaces attempt to input
    **    and output data in approximately 1 KiB chunks. This operand may be used
    **    to set and query the value of this configuration setting. The pointer
    **    passed as the second argument must point to a value of type (int).
    **    If this value is greater than 0, it is used as the new streaming data
    **    chunk size for both input and output. Before returning, the (int) value
    **    pointed to by pArg is set to the final value of the streaming interface
    **    chunk size.
    ** </dl>
    **
    ** This function returns SQLITE_OK if successful, or an SQLite error code
    ** otherwise.
    */
    SQLITE_API int sqlite3session_config(int op, void* pArg);

    /*
    ** CAPI3REF: Values for sqlite3session_config().
    */
#define SQLITE_SESSION_CONFIG_STRMSIZE 1

    /*
    ** Make sure we can call this stuff from C++.
    */
#ifdef __cplusplus
}
#endif

#endif  /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */

/******** End of sqlite3session.h *********/
/******** Begin file fts5.h *********/
/*
** 2014 May 31
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** Interfaces to extend FTS5. Using the interfaces defined in this file,
** FTS5 may be extended with:
**
**     * custom tokenizers, and
**     * custom auxiliary functions.
*/


#ifndef _FTS5_H
#define _FTS5_H


#ifdef __cplusplus
extern "C" {
#endif

    /*************************************************************************
    ** CUSTOM AUXILIARY FUNCTIONS
    **
    ** Virtual table implementations may overload SQL functions by implementing
    ** the sqlite3_module.xFindFunction() method.
    */

    typedef struct Fts5ExtensionApi Fts5ExtensionApi;
    typedef struct Fts5Context Fts5Context;
    typedef struct Fts5PhraseIter Fts5PhraseIter;

    typedef void (*fts5_extension_function)(
        const Fts5ExtensionApi* pApi,   /* API offered by current FTS version */
        Fts5Context* pFts,              /* First arg to pass to pApi functions */
        sqlite3_context* pCtx,          /* Context for returning result/error */
        int nVal,                       /* Number of values in apVal[] array */
        sqlite3_value** apVal           /* Array of trailing arguments */
        );

    struct Fts5PhraseIter {
        const unsigned char* a;
        const unsigned char* b;
    };

    /*
    ** EXTENSION API FUNCTIONS
    **
    ** xUserData(pFts):
    **   Return a copy of the context pointer the extension function was
    **   registered with.
    **
    ** xColumnTotalSize(pFts, iCol, pnToken):
    **   If parameter iCol is less than zero, set output variable *pnToken
    **   to the total number of tokens in the FTS5 table. Or, if iCol is
    **   non-negative but less than the number of columns in the table, return
    **   the total number of tokens in column iCol, considering all rows in
    **   the FTS5 table.
    **
    **   If parameter iCol is greater than or equal to the number of columns
    **   in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
    **   an OOM condition or IO error), an appropriate SQLite error code is
    **   returned.
    **
    ** xColumnCount(pFts):
    **   Return the number of columns in the table.
    **
    ** xColumnSize(pFts, iCol, pnToken):
    **   If parameter iCol is less than zero, set output variable *pnToken
    **   to the total number of tokens in the current row. Or, if iCol is
    **   non-negative but less than the number of columns in the table, set
    **   *pnToken to the number of tokens in column iCol of the current row.
    **
    **   If parameter iCol is greater than or equal to the number of columns
    **   in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
    **   an OOM condition or IO error), an appropriate SQLite error code is
    **   returned.
    **
    **   This function may be quite inefficient if used with an FTS5 table
    **   created with the "columnsize=0" option.
    **
    ** xColumnText:
    **   This function attempts to retrieve the text of column iCol of the
    **   current document. If successful, (*pz) is set to point to a buffer
    **   containing the text in utf-8 encoding, (*pn) is set to the size in bytes
    **   (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
    **   if an error occurs, an SQLite error code is returned and the final values
    **   of (*pz) and (*pn) are undefined.
    **
    ** xPhraseCount:
    **   Returns the number of phrases in the current query expression.
    **
    ** xPhraseSize:
    **   Returns the number of tokens in phrase iPhrase of the query. Phrases
    **   are numbered starting from zero.
    **
    ** xInstCount:
    **   Set *pnInst to the total number of occurrences of all phrases within
    **   the query within the current row. Return SQLITE_OK if successful, or
    **   an error code (i.e. SQLITE_NOMEM) if an error occurs.
    **
    **   This API can be quite slow if used with an FTS5 table created with the
    **   "detail=none" or "detail=column" option. If the FTS5 table is created
    **   with either "detail=none" or "detail=column" and "content=" option
    **   (i.e. if it is a contentless table), then this API always returns 0.
    **
    ** xInst:
    **   Query for the details of phrase match iIdx within the current row.
    **   Phrase matches are numbered starting from zero, so the iIdx argument
    **   should be greater than or equal to zero and smaller than the value
    **   output by xInstCount().
    **
    **   Usually, output parameter *piPhrase is set to the phrase number, *piCol
    **   to the column in which it occurs and *piOff the token offset of the
    **   first token of the phrase. Returns SQLITE_OK if successful, or an error
    **   code (i.e. SQLITE_NOMEM) if an error occurs.
    **
    **   This API can be quite slow if used with an FTS5 table created with the
    **   "detail=none" or "detail=column" option.
    **
    ** xRowid:
    **   Returns the rowid of the current row.
    **
    ** xTokenize:
    **   Tokenize text using the tokenizer belonging to the FTS5 table.
    **
    ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
    **   This API function is used to query the FTS table for phrase iPhrase
    **   of the current query. Specifically, a query equivalent to:
    **
    **       ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
    **
    **   with $p set to a phrase equivalent to the phrase iPhrase of the
    **   current query is executed. Any column filter that applies to
    **   phrase iPhrase of the current query is included in $p. For each
    **   row visited, the callback function passed as the fourth argument
    **   is invoked. The context and API objects passed to the callback
    **   function may be used to access the properties of each matched row.
    **   Invoking Api.xUserData() returns a copy of the pointer passed as
    **   the third argument to pUserData.
    **
    **   If the callback function returns any value other than SQLITE_OK, the
    **   query is abandoned and the xQueryPhrase function returns immediately.
    **   If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
    **   Otherwise, the error code is propagated upwards.
    **
    **   If the query runs to completion without incident, SQLITE_OK is returned.
    **   Or, if some error occurs before the query completes or is aborted by
    **   the callback, an SQLite error code is returned.
    **
    **
    ** xSetAuxdata(pFts5, pAux, xDelete)
    **
    **   Save the pointer passed as the second argument as the extension function's
    **   "auxiliary data". The pointer may then be retrieved by the current or any
    **   future invocation of the same fts5 extension function made as part of
    **   the same MATCH query using the xGetAuxdata() API.
    **
    **   Each extension function is allocated a single auxiliary data slot for
    **   each FTS query (MATCH expression). If the extension function is invoked
    **   more than once for a single FTS query, then all invocations share a
    **   single auxiliary data context.
    **
    **   If there is already an auxiliary data pointer when this function is
    **   invoked, then it is replaced by the new pointer. If an xDelete callback
    **   was specified along with the original pointer, it is invoked at this
    **   point.
    **
    **   The xDelete callback, if one is specified, is also invoked on the
    **   auxiliary data pointer after the FTS5 query has finished.
    **
    **   If an error (e.g. an OOM condition) occurs within this function,
    **   the auxiliary data is set to NULL and an error code returned. If the
    **   xDelete parameter was not NULL, it is invoked on the auxiliary data
    **   pointer before returning.
    **
    **
    ** xGetAuxdata(pFts5, bClear)
    **
    **   Returns the current auxiliary data pointer for the fts5 extension
    **   function. See the xSetAuxdata() method for details.
    **
    **   If the bClear argument is non-zero, then the auxiliary data is cleared
    **   (set to NULL) before this function returns. In this case the xDelete,
    **   if any, is not invoked.
    **
    **
    ** xRowCount(pFts5, pnRow)
    **
    **   This function is used to retrieve the total number of rows in the table.
    **   In other words, the same value that would be returned by:
    **
    **        SELECT count(*) FROM ftstable;
    **
    ** xPhraseFirst()
    **   This function is used, along with type Fts5PhraseIter and the xPhraseNext
    **   method, to iterate through all instances of a single query phrase within
    **   the current row. This is the same information as is accessible via the
    **   xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
    **   to use, this API may be faster under some circumstances. To iterate
    **   through instances of phrase iPhrase, use the following code:
    **
    **       Fts5PhraseIter iter;
    **       int iCol, iOff;
    **       for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
    **           iCol>=0;
    **           pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
    **       ){
    **         // An instance of phrase iPhrase at offset iOff of column iCol
    **       }
    **
    **   The Fts5PhraseIter structure is defined above. Applications should not
    **   modify this structure directly - it should only be used as shown above
    **   with the xPhraseFirst() and xPhraseNext() API methods (and by
    **   xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
    **
    **   This API can be quite slow if used with an FTS5 table created with the
    **   "detail=none" or "detail=column" option. If the FTS5 table is created
    **   with either "detail=none" or "detail=column" and "content=" option
    **   (i.e. if it is a contentless table), then this API always iterates
    **   through an empty set (all calls to xPhraseFirst() set iCol to -1).
    **
    ** xPhraseNext()
    **   See xPhraseFirst above.
    **
    ** xPhraseFirstColumn()
    **   This function and xPhraseNextColumn() are similar to the xPhraseFirst()
    **   and xPhraseNext() APIs described above. The difference is that instead
    **   of iterating through all instances of a phrase in the current row, these
    **   APIs are used to iterate through the set of columns in the current row
    **   that contain one or more instances of a specified phrase. For example:
    **
    **       Fts5PhraseIter iter;
    **       int iCol;
    **       for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
    **           iCol>=0;
    **           pApi->xPhraseNextColumn(pFts, &iter, &iCol)
    **       ){
    **         // Column iCol contains at least one instance of phrase iPhrase
    **       }
    **
    **   This API can be quite slow if used with an FTS5 table created with the
    **   "detail=none" option. If the FTS5 table is created with either
    **   "detail=none" "content=" option (i.e. if it is a contentless table),
    **   then this API always iterates through an empty set (all calls to
    **   xPhraseFirstColumn() set iCol to -1).
    **
    **   The information accessed using this API and its companion
    **   xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
    **   (or xInst/xInstCount). The chief advantage of this API is that it is
    **   significantly more efficient than those alternatives when used with
    **   "detail=column" tables.
    **
    ** xPhraseNextColumn()
    **   See xPhraseFirstColumn above.
    */
    struct Fts5ExtensionApi {
        int iVersion;                   /* Currently always set to 3 */

        void* (*xUserData)(Fts5Context*);

        int (*xColumnCount)(Fts5Context*);
        int (*xRowCount)(Fts5Context*, sqlite3_int64* pnRow);
        int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64* pnToken);

        int (*xTokenize)(Fts5Context*,
            const char* pText, int nText, /* Text to tokenize */
            void* pCtx,                   /* Context passed to xToken() */
            int (*xToken)(void*, int, const char*, int, int, int)       /* Callback */
            );

        int (*xPhraseCount)(Fts5Context*);
        int (*xPhraseSize)(Fts5Context*, int iPhrase);

        int (*xInstCount)(Fts5Context*, int* pnInst);
        int (*xInst)(Fts5Context*, int iIdx, int* piPhrase, int* piCol, int* piOff);

        sqlite3_int64(*xRowid)(Fts5Context*);
        int (*xColumnText)(Fts5Context*, int iCol, const char** pz, int* pn);
        int (*xColumnSize)(Fts5Context*, int iCol, int* pnToken);

        int (*xQueryPhrase)(Fts5Context*, int iPhrase, void* pUserData,
            int(*)(const Fts5ExtensionApi*, Fts5Context*, void*)
            );
        int (*xSetAuxdata)(Fts5Context*, void* pAux, void(*xDelete)(void*));
        void* (*xGetAuxdata)(Fts5Context*, int bClear);

        int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
        void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int* piCol, int* piOff);

        int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
        void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int* piCol);
    };

    /*
    ** CUSTOM AUXILIARY FUNCTIONS
    *************************************************************************/

    /*************************************************************************
    ** CUSTOM TOKENIZERS
    **
    ** Applications may also register custom tokenizer types. A tokenizer
    ** is registered by providing fts5 with a populated instance of the
    ** following structure. All structure methods must be defined, setting
    ** any member of the fts5_tokenizer struct to NULL leads to undefined
    ** behaviour. The structure methods are expected to function as follows:
    **
    ** xCreate:
    **   This function is used to allocate and initialize a tokenizer instance.
    **   A tokenizer instance is required to actually tokenize text.
    **
    **   The first argument passed to this function is a copy of the (void*)
    **   pointer provided by the application when the fts5_tokenizer object
    **   was registered with FTS5 (the third argument to xCreateTokenizer()).
    **   The second and third arguments are an array of nul-terminated strings
    **   containing the tokenizer arguments, if any, specified following the
    **   tokenizer name as part of the CREATE VIRTUAL TABLE statement used
    **   to create the FTS5 table.
    **
    **   The final argument is an output variable. If successful, (*ppOut)
    **   should be set to point to the new tokenizer handle and SQLITE_OK
    **   returned. If an error occurs, some value other than SQLITE_OK should
    **   be returned. In this case, fts5 assumes that the final value of *ppOut
    **   is undefined.
    **
    ** xDelete:
    **   This function is invoked to delete a tokenizer handle previously
    **   allocated using xCreate(). Fts5 guarantees that this function will
    **   be invoked exactly once for each successful call to xCreate().
    **
    ** xTokenize:
    **   This function is expected to tokenize the nText byte string indicated
    **   by argument pText. pText may or may not be nul-terminated. The first
    **   argument passed to this function is a pointer to an Fts5Tokenizer object
    **   returned by an earlier call to xCreate().
    **
    **   The second argument indicates the reason that FTS5 is requesting
    **   tokenization of the supplied text. This is always one of the following
    **   four values:
    **
    **   <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
    **            or removed from the FTS table. The tokenizer is being invoked to
    **            determine the set of tokens to add to (or delete from) the
    **            FTS index.
    **
    **       <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed
    **            against the FTS index. The tokenizer is being called to tokenize
    **            a bareword or quoted string specified as part of the query.
    **
    **       <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
    **            FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
    **            followed by a "*" character, indicating that the last token
    **            returned by the tokenizer will be treated as a token prefix.
    **
    **       <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to
    **            satisfy an fts5_api.xTokenize() request made by an auxiliary
    **            function. Or an fts5_api.xColumnSize() request made by the same
    **            on a columnsize=0 database.
    **   </ul>
    **
    **   For each token in the input string, the supplied callback xToken() must
    **   be invoked. The first argument to it should be a copy of the pointer
    **   passed as the second argument to xTokenize(). The third and fourth
    **   arguments are a pointer to a buffer containing the token text, and the
    **   size of the token in bytes. The 4th and 5th arguments are the byte offsets
    **   of the first byte of and first byte immediately following the text from
    **   which the token is derived within the input.
    **
    **   The second argument passed to the xToken() callback ("tflags") should
    **   normally be set to 0. The exception is if the tokenizer supports
    **   synonyms. In this case see the discussion below for details.
    **
    **   FTS5 assumes the xToken() callback is invoked for each token in the
    **   order that they occur within the input text.
    **
    **   If an xToken() callback returns any value other than SQLITE_OK, then
    **   the tokenization should be abandoned and the xTokenize() method should
    **   immediately return a copy of the xToken() return value. Or, if the
    **   input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
    **   if an error occurs with the xTokenize() implementation itself, it
    **   may abandon the tokenization and return any error code other than
    **   SQLITE_OK or SQLITE_DONE.
    **
    ** SYNONYM SUPPORT
    **
    **   Custom tokenizers may also support synonyms. Consider a case in which a
    **   user wishes to query for a phrase such as "first place". Using the
    **   built-in tokenizers, the FTS5 query 'first + place' will match instances
    **   of "first place" within the document set, but not alternative forms
    **   such as "1st place". In some applications, it would be better to match
    **   all instances of "first place" or "1st place" regardless of which form
    **   the user specified in the MATCH query text.
    **
    **   There are several ways to approach this in FTS5:
    **
    **   <ol><li> By mapping all synonyms to a single token. In this case, using
    **            the above example, this means that the tokenizer returns the
    **            same token for inputs "first" and "1st". Say that token is in
    **            fact "first", so that when the user inserts the document "I won
    **            1st place" entries are added to the index for tokens "i", "won",
    **            "first" and "place". If the user then queries for '1st + place',
    **            the tokenizer substitutes "first" for "1st" and the query works
    **            as expected.
    **
    **       <li> By querying the index for all synonyms of each query term
    **            separately. In this case, when tokenizing query text, the
    **            tokenizer may provide multiple synonyms for a single term
    **            within the document. FTS5 then queries the index for each
    **            synonym individually. For example, faced with the query:
    **
    **   <codeblock>
    **     ... MATCH 'first place'</codeblock>
    **
    **            the tokenizer offers both "1st" and "first" as synonyms for the
    **            first token in the MATCH query and FTS5 effectively runs a query
    **            similar to:
    **
    **   <codeblock>
    **     ... MATCH '(first OR 1st) place'</codeblock>
    **
    **            except that, for the purposes of auxiliary functions, the query
    **            still appears to contain just two phrases - "(first OR 1st)"
    **            being treated as a single phrase.
    **
    **       <li> By adding multiple synonyms for a single term to the FTS index.
    **            Using this method, when tokenizing document text, the tokenizer
    **            provides multiple synonyms for each token. So that when a
    **            document such as "I won first place" is tokenized, entries are
    **            added to the FTS index for "i", "won", "first", "1st" and
    **            "place".
    **
    **            This way, even if the tokenizer does not provide synonyms
    **            when tokenizing query text (it should not - to do so would be
    **            inefficient), it doesn't matter if the user queries for
    **            'first + place' or '1st + place', as there are entries in the
    **            FTS index corresponding to both forms of the first token.
    **   </ol>
    **
    **   Whether it is parsing document or query text, any call to xToken that
    **   specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
    **   is considered to supply a synonym for the previous token. For example,
    **   when parsing the document "I won first place", a tokenizer that supports
    **   synonyms would call xToken() 5 times, as follows:
    **
    **   <codeblock>
    **       xToken(pCtx, 0, "i",                      1,  0,  1);
    **       xToken(pCtx, 0, "won",                    3,  2,  5);
    **       xToken(pCtx, 0, "first",                  5,  6, 11);
    **       xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3,  6, 11);
    **       xToken(pCtx, 0, "place",                  5, 12, 17);
    **</codeblock>
    **
    **   It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
    **   xToken() is called. Multiple synonyms may be specified for a single token
    **   by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence.
    **   There is no limit to the number of synonyms that may be provided for a
    **   single token.
    **
    **   In many cases, method (1) above is the best approach. It does not add
    **   extra data to the FTS index or require FTS5 to query for multiple terms,
    **   so it is efficient in terms of disk space and query speed. However, it
    **   does not support prefix queries very well. If, as suggested above, the
    **   token "first" is substituted for "1st" by the tokenizer, then the query:
    **
    **   <codeblock>
    **     ... MATCH '1s*'</codeblock>
    **
    **   will not match documents that contain the token "1st" (as the tokenizer
    **   will probably not map "1s" to any prefix of "first").
    **
    **   For full prefix support, method (3) may be preferred. In this case,
    **   because the index contains entries for both "first" and "1st", prefix
    **   queries such as 'fi*' or '1s*' will match correctly. However, because
    **   extra entries are added to the FTS index, this method uses more space
    **   within the database.
    **
    **   Method (2) offers a midpoint between (1) and (3). Using this method,
    **   a query such as '1s*' will match documents that contain the literal
    **   token "1st", but not "first" (assuming the tokenizer is not able to
    **   provide synonyms for prefixes). However, a non-prefix query like '1st'
    **   will match against "1st" and "first". This method does not require
    **   extra disk space, as no extra entries are added to the FTS index.
    **   On the other hand, it may require more CPU cycles to run MATCH queries,
    **   as separate queries of the FTS index are required for each synonym.
    **
    **   When using methods (2) or (3), it is important that the tokenizer only
    **   provide synonyms when tokenizing document text (method (2)) or query
    **   text (method (3)), not both. Doing so will not cause any errors, but is
    **   inefficient.
    */
    typedef struct Fts5Tokenizer Fts5Tokenizer;
    typedef struct fts5_tokenizer fts5_tokenizer;
    struct fts5_tokenizer {
        int (*xCreate)(void*, const char** azArg, int nArg, Fts5Tokenizer** ppOut);
        void (*xDelete)(Fts5Tokenizer*);
        int (*xTokenize)(Fts5Tokenizer*,
            void* pCtx,
            int flags,            /* Mask of FTS5_TOKENIZE_* flags */
            const char* pText, int nText,
            int (*xToken)(
                void* pCtx,         /* Copy of 2nd argument to xTokenize() */
                int tflags,         /* Mask of FTS5_TOKEN_* flags */
                const char* pToken, /* Pointer to buffer containing token */
                int nToken,         /* Size of token in bytes */
                int iStart,         /* Byte offset of token within input text */
                int iEnd            /* Byte offset of end of token within input text */
                )
            );
    };

    /* Flags that may be passed as the third argument to xTokenize() */
#define FTS5_TOKENIZE_QUERY     0x0001
#define FTS5_TOKENIZE_PREFIX    0x0002
#define FTS5_TOKENIZE_DOCUMENT  0x0004
#define FTS5_TOKENIZE_AUX       0x0008

/* Flags that may be passed by the tokenizer implementation back to FTS5
** as the third argument to the supplied xToken callback. */
#define FTS5_TOKEN_COLOCATED    0x0001      /* Same position as prev. token */

/*
** END OF CUSTOM TOKENIZERS
*************************************************************************/

/*************************************************************************
** FTS5 EXTENSION REGISTRATION API
*/
    typedef struct fts5_api fts5_api;
    struct fts5_api {
        int iVersion;                   /* Currently always set to 2 */

        /* Create a new tokenizer */
        int (*xCreateTokenizer)(
            fts5_api* pApi,
            const char* zName,
            void* pContext,
            fts5_tokenizer* pTokenizer,
            void (*xDestroy)(void*)
            );

        /* Find an existing tokenizer */
        int (*xFindTokenizer)(
            fts5_api* pApi,
            const char* zName,
            void** ppContext,
            fts5_tokenizer* pTokenizer
            );

        /* Create a new auxiliary function */
        int (*xCreateFunction)(
            fts5_api* pApi,
            const char* zName,
            void* pContext,
            fts5_extension_function xFunction,
            void (*xDestroy)(void*)
            );
    };

    /*
    ** END OF REGISTRATION API
    *************************************************************************/

#ifdef __cplusplus
}  /* end of the 'extern "C"' block */
#endif

#endif /* _FTS5_H */

/******** End of fts5.h *********/
